When he was 10, Rajesh Bohra Sangeeta watched his grandmother refuse food and water for 35 days in their family home in India's western state of Rajasthan, until she grew weak and died.

"There was no suffering," he said. And nobody wept when she died, instead they "celebrated".

The 85-year-old was not sick. She had decided to take Santhara — a fast practised by India's 4.5 million strong Jain religious community, where followers give up food and water to purify the soul in preparation for death.

Now a lawyer, Mr Sangeeta was among many Jains stunned last month when Rajasthan's High Court outlawed the ritual, comparing it to suicide, which is punishable by jail in India.

The decision sent shockwaves through all of India's Jain community. Thousands marched in Rajasthan's capital Jaipur and in cities around the country.

Followers of the religion protested that suicide in fact conflicts with their commitment to non-violence, an adherence stricter than Buddhism.

Jain groups are now preparing to take their fight to be able to fast until death to the Supreme Court of India, which this week stayed the High Court's order.

"Jains are coming together to fight this," said Rajeev Doddannavar, president of the Samasth Jain Samaj organisation, who will join the legal battle.

"We'll demonstrate that suicide and willingly giving [up] the life in Santhara are two very different things."

A Jain nun sits waiting to bless followers inside Choti Dadabari Jain temple. ( Alys Francis )

Lawyer claims Santhara just a way of getting rid of the elderly

Jaipur lawyer Nikhil Soni moved to outlaw Santhara in 2006, after seeing a woman suffering from cancer undertake the practice in a Rajasthan village.

Mr Soni alleged the 60-year-old woman appeared to ask for food and water, but her voice was drowned out by crowds chanting religious songs and she died.

At the time, Mr Soni was quoted as saying the sight left him shaken and convinced him Santhara was a means for "family to get rid of the economic burden of caring for its elderly".

He filed a court action seeking to have the fast declared illegal, calling it "abhorrent to modern thinking" and unconstitutional and arguing that India's constitution does not guarantee the right to death.

Last month, Rajasthan High Court justices Sunil Ambwani and Veerendr Singh Siradhana directed authorities to treat the practice as suicide and punishable under the Indian Penal Code, which allows for jail terms of up to 10 years for attempting and abetting suicide.

The judgement noted claims in court that families would not accept a person changing their mind after vowing to take Santhara.

The court heard some families forced members to complete the process, "sometimes tied to the chair or bed".

The Jains' fast was also compared to the banned Hindu practice of Sati, where women immolate themselves on their husband's funeral pyre.

A young boy visits Choti Dadabari Jain temple, New Delhi, with traditional 'kajal' rimmed eyes, believed to ward off the evil eye. ( Alys Francis )

Jain groups have now appealed to the Supreme Court to overturn the judgement, saying it violates their constitutional right to religious freedom.

Relevant parties have been notified they must attend the appeal. No hearing date has been set.

"The only instance where the court can ban a religious practice is if it is immoral or against the public order, like in the case of Sati," said former High Court judge Pana Chand Jain, who is assisting the Jains in the case.

"Santhara is not against the public order, neither is it immoral."

The former judge said the court was not given enough information to appraise the fundamentals of Jainism and see how Santhara differs from suicide.

Jains argue the practice is centuries old and stems from their belief in renouncing material pleasures like food. Regular fasting is routine for followers.

The founder of the prominent Jain newspaper Ahimsa Times, AK Jain, said Santhara is generally only taken by sick or elderly people who have fulfilled their worldly responsibilities and feel their "days are numbered".

"It's not a common practice," he explained.

It is not known how many people take the fast each year, but he estimated it was fewer than 500.

A woman prostrates herself in prayer before idol statues in Choti Dadabari Jain temple, New Delhi.

Wandering saints enlisted to help cause

Followers need approval from family and religious elders before starting Santhara, and the fast is conducted under strict conditions in a peaceful, celebratory atmosphere, AK Jain said.

"Suicide is something absolutely different," he said.

Jain groups are reaching out to their declared living saints, and nuns, for advice on ancient religious scriptures to support their case.

The ascetics can be difficult to contact, having renounced all ties and committed themselves to a lifetime of travelling. But it is easier to catch up with them now, as September is the last month of India's monsoon season, when they limit movement to avoid squashing bugs.

Sulakshna Shriji is seeing out the rains in Choti Dadabari Jain temple in New Delhi. Sitting on a white marble floor, the 62-year-old Jain nun said she is dismayed that Santhara had been criminalised.

"The judgement is an attack on religion," she declared.

But Ms Shriji, who became a nun when she was 10, doubts followers will stop taking the fast, regardless of the final court decision.

"It will be almost impossible for them to agree to any ruling against their religion," she said.