You can go for a technomanagerial career
You can start your own firm with your ideas and projects.
You can go and start coaching people for GATE examination .
You can join a college as a faculty, mostly assistant professor and then join part time PhD or do PhD via QIP.
You can write gate again and attempt PSU or even go for patent examiner and othwr govt jobs
You can join research in India or abroad for further research and academic exposure.
You can join research labs as project associate to further your chances of PhD or research in future
Obviously you can work in a corporate career in a MNC or any other organization.
Some of the colleges are not able to offer core jobs so you can join IT sector.