Hey loukik.

See in my point of view u should be going for IIIT PUNE as it is one of the good govt engineering college to pursue ur higher studies in the field of ur interest under btech courses. Manipal and VIT that too Chennai campus is not a good option in front of the IIIT as they are private Institution and also are not sure about ur good future as these govt colleges are. 

Hope you got Ur point. Ask if any query. Good luck