NEW DELHI: Safety audit of the Goods and Services Tax Network (GSTN), an information technology backbone of the Goods and Services Tax, is being carried out by security agencies ahead of its roll-out from next month.The process of granting national security clearance to the GSTN is going on and agencies such as Intelligence Bureau (IB) and National Technical and Research Organisation (NTRO) have been roped in for it, official sources said today.Five private institutions have 51 per cent equity in the GSTN -- HDFC Bank Ltd (10 per cent), HDFC Ltd (10 per cent), ICICI Bank Ltd (10 per cent), NSE Strategic Investment Corporation Ltd (10 per cent) and LIC Housing Finance Limited (11 per cent).The central government has 24.5 per cent equity in the GSTN, a not-for-profit private limited company, whereas state governments, two Union territories and the empowered committee of state finance ministers together hold another 24.5 per cent stake in it.The finance ministry is looking into the GSTN with respect to economic security, whereas the home ministry is examining any threat to national security by any of the stakeholders in the company, the sources said.The procedure of grant of security clearance to the GSTN involves background checking of office-bearers and others concerned.The Centre plans to roll out the GST , which will subsume a number of central and state taxes such as excise duty, service tax and Value Added Tax (VAT), from July 1.BJP MP Subramanian Swamy had earlier opposed the majority stake for private entities in the GSTN and had written to Prime Minister Narendra Modi in this regard.The Centre has rejected an RTI plea seeking details of security clearance given to the GSTN, saying the information was exempted as it relates to national security matter.