Initially you'll need to give TCS-NQT, pool campus or off campus. Depending on your performance in that test, it's relative selection so it's still possible to get prime selection if you aren't able to pass all test cases in certain scenarios. Aptitude is one of the aspects of NQT which should never be taken lightly, as both technical and aptitude cutoffs and scores affect your selection. You can check the sections in nqt exam for more clarity. After clearing this you'll get interview mail stating your potential position (ninja, digital or prime). It's possible that a person appearing for an interview for prime is given an offer of ninja if underperformed. You can expect 3 'fields' of interview (but effectively 2 interviews). In my case I went through just one round of 2 panel interview with technical and behavioral interview, but general protocol is a 2 panel interview followed by an hr interview.