Explanation:

Indian federalism was designed on the basis of working of the federalism in USA, Canada and Australia. Yet it deviates from those federalism in many respects and establishes its own distinctive features. The nature of Indian Constitution can be understood as it is: Federal with unitary features; Unitary with federal features and Quasi-federal

• Quasi federal nature of Indian Constitution: Article 1 of the Constitution of India states that ‘India that is Bharat shall be a union of states’. Indian model of federalism is called the quasi-federal system as it contains major features of both a federation and union. 
• In short it may be concluded that the Indian constitution is a combination of both unitary and federal state where more features are there for federal. Thus Indian constitution is mainly federal with some unitary features for national unity and growth.

Hence option 4th is correct.