Hey!

For MTech you are required to give either state or central entrance examinations.

GATE is the entrance exam which is accepted in almost all Universities and colleges around India. Apart from GATE there are several other entrance exams like UPCET, AP PGECET, TS PGCET, Karnatak PGCET, TANCET, OJEE PG, Gujarat PGCET, VITMEE, IIIT Delhi MTech Entrance Exam. There  are several others you can check out the whole list over here in this link below.

https://www.google.com/amp/s/engineering.careers360.com/articles/mtech-entrance-exams/amp

For GATE 2022 the application process starts from August 30, 2021.

VITMEE and TS PGCET the process will begin by March 2022. As for Gujarat PGCET, it begins in June and OJEE PG begins by February. For IIIT the last dates are around May.

These are based on previous years. As you see it's throughout the year. You have to keep checking for the exam that you want to give. For all the exams you can check out the link I have mentioned above.

After entrance exam, cut off list will be released and then the admission process starts.

Hope this answers your query.