Hello Teja,

Graduate Aptitude Test in Engineering (GATE) is a national-level post-graduate entrance exam that is jointly conducted by the seven IITs (Bombay, Delhi, Kanpur, Guwahati, Kharagpur, Madras and Roorkee) and the Indian Institute of Science (IISc), Bangalore for admission to M.Tech programmes offered by government as well as many private institutes.

GATE 2019 was organized by Indian Institute of Technology (IIT) Madras in online mode on February 2, 3, 9 and 10, 2019.

COAP is conducted by IITs (IIT Madras in 2019) to facilitate admissions of aspirants in M.Tech programs of IITs. The candidates after applying to the IITs of their choice on the basis of the GATE scores, have to necessrily apply for COAP.

CCMT is conducted for admissions to M.Tech programs of NITs by different NITs (NIT Rourkela in 2019).

As for your question, you will have to get a renewed OBC category proof certificate.

For more inforamtion, follow the below links:

Https://engineering.careers360.com/articles/ccmt

Https://engineering.careers360.com/articles/gate-coap