The Parliament of India is the supreme legislative body of India and comprises of
- the President,
- the Lok Sabha and
- the Rajya Sabha.
The President is the head of the body and has full powers to summon and prorogue either house of Parliament or to dissolve Lok Sabha.
Yes, the Parliament is the sovereign body of India. It is the single largest legislative body and has supreme power over all other government institutions, including executive or judicial bodies. The Parliament may repeat or change or dissolve any decision made by it earlier so it is not bound by any law.
Hence, we may say that Parliament is the sovereign body of the Indian nation. 
