Has this modification been approved or is it something that Indian army would test and then decided? I find this to be a breach of the safety protocol followed by most world militaries.
Soldiers on the field sit directly on the tank in much more dangerous spots (i.e on the hull in front of the turret and gun etc) to use the tank as a personnel carrier etc I have seen in many worldwide battle situations....there are safety protocols/common sense (hopefully) made aware to tank crew regarding those situations.
I don't see any real safety protocol being violated with the seats, I think its dealt with by putting the tank as observer status "mode", so it will not fire anything, RWS will be locked/turned off etc.. and turret will be locked given it looks like given there's someone standing behind them too. I remember they did this kind of arrangement for non military VIP having a ride/tour on it too, like President, defence minister etc.