Hello Dear,

Backlogs or supply don't really matter because they just need a candidate who is capable of facing hardships at m.tech at IITs.But the main point is that you need to prove yourself in written test and PI(personal interview).
Because a cgpa of >=6 is not so convincing, but still if you manage to ace WRITTEN TEST/PI that really make them think about your application.
Apart from these don't forget to maintain a good gate score which is a pre-requisite.

All the best and good luck

Hii

I guess you are asking that suppose if you get supple in 8th Sem......?? Right ?
If this is the question then the answer is :
No you can't able to take admission in M.tech courses if you get supple in 8th sem , you may apply for M.Tech but before the starting of the admission process you have to clear your supple such that you may present your degree during the time of counselling.

Good luck