The fundamental issue is 
WHO THE HELL WILL SCORE RUNS FOR US?
Put runs on the board and India will win the series.
But who will score the damn runs lol.
		
		
	 
It's a bigger issue than that.
Runs are the bigger issue, yes, but one good partnership can change the game.
Fundamentally, India is in a very poor situation because neither of their tailenders can bat to save their own lives, they are liabilities. You need to have competent tailenders because those crucial partnerships, those crucial 40-50 runs can make a great difference.
Personally, I think that Rohit Sharma is not cut for test cricket. His technique against the moving ball is poor, and he is unable to capitalize on the starts he gets in overseas tours. Against Broad and Anderson, I can easily see India being a wicket down within the first 5 overs. However, his performances in the recent India vs England test series will keep him in that opening slot.
Prithvi would be a horrible choice as an opener, the gap between his bat and pad is enormous. His poor foot movement, coupled with his natural instinct to attack every ball, means that Anderson would literally destroy him within a few balls.
Pujara has been riding the boat without any performances in the last few series, and I doubt England will be the place he steps up. 
India's top 3, right now, looks incredibly shaky, and it is not a good sign going into a major test series.
Having a vulnerable top order, coupled with the fact that you don't get runs down the order, means only one thing: the key to this series lies in the form of Virat Kohli and Ajinkya Rahane. If they perform, India might drag themselves to some formidable totals, but if they don't, major collapses will occur. I also think Jadeja's batting will play a role.
I can easily predict that England would win if India doesn't hit the ground running, but I do think that India can still challenge England if their squad selection is good.
I would play the following team:
Rohit Sharma (you have to hope that he can hit a few 50+ scores and carry on once he gets set)
Mayank Agarwal 
KL Rahul
Virat Kohli
Ajinkya Rahane
Hanuma Vihari
Ravindra Jadeja
Shardul Thakur/Ravichandran Ashwin
Ishant Sharma
Mohammad Shami
Mohammad Siraj/Jasprit Bumrah