NEW DELHI: Tamil and Malayalam speaking populations are falling across most states in north India even as Tamil Nadu and Kerala are seeing a huge jump in the number of Hindi, Bengali, Assamese and Odia speakers. Just-released data from the 2011 census on mother tongues seems to indicate a reverse migration trend from earlier decades when people from the two southern states migrated in large numbers to the north.Instead, a large number of people from the two states are now migrating within the south, with Karnataka seeing a significant influx. Delhi saw a fall in numbers of both Tamil and Malyali speakers between the 2001 and 2011 censuses.Maharashtra, once a favoured destination for south Indians, mostly because of Mumbai, witnessed a decline in Kannada, Telugu, Tamil and Malayalam speakers. In the north, the highest growth in Malayali population between the 2001 and 2011 censuses was in Uttar Pradesh , perhaps because of Noida, while that of the Tamilian population was in Haryana, which might be because of Gurgaon.But the absolute numbers involved are small compared with the migration of Tamilians and Malayalis within south India. While Tamil Nadu and Kerala saw the highest growth in Hindi speakers among all states, all of south India is witnessing a steady increase, with the highest absolute number of Hindi speakers in the region being in Karnataka and Andhra Pradesh.Kerala also saw the highest growth in Assamese and Bengalis even if the absolute numbers were not as high as in Maharashtra or Karnataka. The number of Nepali speakers too is growing fast in the south.In both cases, there is a growth of about 24% in populations speaking the respective languages.