You can't really blame India for opposing the Decision Review System. There are several reasons for this
1) India's first experience with the DRS wasn't very pleasant. India was playing against Sri Lanka and some very crucial decisions went to Sri Lanka's way and India lost the first test match of the series. However this is not a valid reason to oppose the DRS.
2) DRS was then used in the 2011 World cup, everything was going fine until Ian Bell was given not out even after the ball was clearly hitting the middle and off stump and he was given not out under some peculiar rule that if the batsman is 2.5 metres away from the stumps then he cannot be given LBW this was contrary to the decision given by Simon Taufell in the 2009 Champions trophy in South Africa where MS Dhoni was given out lbw when he was atleast 4 metres away from the stumps. India found this rule very absurd.
3) The hotspot technology that is used to determine whether the ball has struck the batsman, bat or pad is not true always. The company that provides this technology claims that this technology is 95% efficient. In the India-England ODI Series in 2011, there were controversial decisions based on the Hot Spot technology going against India's Rahul Dravid on more than one occasion where Hot Spot replays proved inconclusive and yet Dravid was given out. On one occasion, there seemed to be a nick which Hot Spot wasn't able to detect. These incidents threw the role of Hot Spot technology into doubt once again.