There is an entrance exam MUST to enter good colleges and based on your score in the exam you shall be further shortlisted for other rounds like GD/PI and WAT.

There can be direct admission process as well but again you will have to bear the cost as its quite expensive and its officially not public.

You can apply for competitive exams as the admission cycle is ongoing and applications for all top exams like CAT, XAT is going on.

You can apply from here:

CAT applications

XAT applications

Try to give as many exams to get admission in MBA if you are determined to get admission this academic year.
Also remeber the basic eleigibility criteria is graduation with 50% in most of the exams except MAT, XAT. Rest you can check the criteria individually as well.

Good luck!!