“I will certainly come whether it rains or not” is right answer and it is applicable for the student to get right answer from it.
Therefore the student can check out answer from this and updated with right answer for your entire question with no risk and trouble of it.
Here is your answer,
Question = Even if it rains i shall come,means sentence completion ?
answer = I will certainly come whether it rains or not.
Hope it helps you !
ek baar apni sis se baat karna shayad mood change hojaye