I dont think dropping KL Rahul is the right way to go. He is just now starting to get a semblance of a consistent run in test cricket. And purely for his age, he should stay in the XI for this whole series. With Dhawan falling out of favor and Vijay definitely on his way out of Indian cricket, Rahul needs persistence despite the failures. I would slot Agarwal in for Vijay, for the Boxing Day test. Maybe the aggression and younger blood of Agarwal might give Rahul the role of holding his end up while Agarwal takes up the aggressor role, and that could work for Rahul.
Rahul
Agarwal
Pujara
Kohli
Rahane
Pant
Hardik
Jadeja
Ishant/Bhuvi/Kuldeep
Shami
Bumrah
I somehow feel Ashwin should not be rushed through. Bring him in for Sydney, thereby giving him extra time to recover. Dont make the same mistake that was done in England. If a 2nd spinner is needed, play Kuldeep for Ishant and just have Shami and Bumrah as the seamers. Even if 2 spinners are not needed, Bhuvi can replace Ishant, who I feel could have a break.