Hello,

After jee main, you will go under counselling process where colleges will be assigned to you as per your rank. After counselling process, you will get a call from college to report at the college for the official process of admission.

For Btech and Barch all the process is same until admission. After admission, as per your stream you will study your branch and by the end of your graduation you will apply for job or go for higher studies depending at the time you will graduate and  you will pass out from the college.

It is short but it is a very long process. You will know everything and understand it so have patience and do things carefully.

Hope it helps!