GATE is a National-level post-graduate entrance exam for the admission to M.Tech programmes offered by government as well as many private institutes. As per the eligibility you should have completed your Bachelor’s degree in Engineering/Technology or Master’s degree (M.Sc) in any relevant science subject or must be in the final year of the programme. You can check the further information about GATE Entrance Exam with the given below link.

https://engineering.careers360.com/articles/gate-eligibility-criteria

If you explain the particular college to which you wish to know the fees structure  then I can help you better. Gate qualifiers get stipend of Rs.12400/-

Good Luck!