Option 1: Try for offcampus placements. Try at good companies-- usually they consider from Tier 1,2 colleges only but if you can prove your coding skill somehow, you may get a call.
Option 2: Attend M.Tech. Research/M.Sc. interviews. May be even in winter session also. I'm not sure of the feasibility but there might be an option for you to do your current thesis under the guidance in say IITM. In that case either you can do your MS there in less than 2 years or even a Ph.D.
Ph.D. might not be good option for you currently as you are interested in coding and not much interested in any specific area of research. But one thing I want to say is in India and even many other places, research jobs are paid better than development jobs - you can see IBM IRL, MS Research, etc. If you get interest, you can come back any time and do a Ph.D. But very few people can come back once they join a job.
Repeating GATE might not be a good option. Because unless you give a good effort you might not be able to improve the current rank. So, you must have the will for doing this. Going from rank 943 to say 100 will need higher effort than going from 10000 to say 3000. But since you have nothing to loose being in pre final year, even if you do not prepare much you can just give GATE 2018.
