You can get admission M.tech in govt. colleges in Kerala. For that you have to apply through the DTE website. You can apply if you have 60% aggregate marks in B.tech degree, if you've cleared B.Tech and if you're a final year student, you should've cleared all the papers upto 6th semester. For more details regarding M.Tech, like courses offered and seat availability, please check this link below or the DTE website.-

http://admissions.dtekerala.gov.in/downloads/mtech2017.pdf

Good Luck.