Which of the following is Non-Federal feature of the Indian Constitution ?

Single Constitution is considered a non-federal feature of the Indian Constitution because, in a truly federal system, each unit (state) would have its own constitution, like in the United States. However, in India, there is a single constitution for both the Union and the States. Independent Judiciary  , Written Constitution  , and Division of Powers   are federal features as they support the division of authority and the independence of states within the federation.