Most of the admission to Engineering College happen through the entrance exam for very few college which have no reputation at all can give u admission just on the basis of class 12th marks but most of the college will give u admission on the basis of entrance exam there for you need to appear for the entrance exam for the college generally Gmail is most preferred because it accepted by most of the colleges across the country and some of the state government college also give admission on the basis of JEE main score there for you should appear for JEE main and score well in the exam if you score very well then you can let up to NIT colleges and you will be eligible to appear for JEE advanced and in case of JEE advanced you qualify it then you will be able to get into the most premier Institute of the country for engineering in IIT there are lot of options for engineering in India so based on your preference and your prepare label you can go to college.