Which of the following judgements stated that 'Secularism' and 'Federalism are the basic features of the Indian Constitution?

The concept of basic structure was given by supreme Court in Keshwananda Bharti case, 1973. At that time court did not define what is basic structure. Supreme court in subsequent cases defined some of the basic structures. In S.R. Bommai case, 1994 which was related , to misuse of article 356 i.e, state emergency or President's rule, Supreme Court stated 'Secularism' and 'Federalism' as basic structures of constitution.