Can anyone guide me for the WITCHA companies' fresher role.

As I am in my 8th semester and want to be placed in the technical domain, I want to know about the process of applying to exams like TCS NQT, Infosys( SP, DSE role), etc. My college is not providing any updates or support from their side. So, if any senior can give me a brief summary for the registration and preparation of these exams. I will also appreciate any other help and guidance for other companies except from these.