i know they want him to over react but what is stopping him to react tactfully what do you propose ?
Milk this incident to gain as much public opinion as possible, they must have lost many on the fence supporters in this incident, don't let anything get in the way of passage of GST as their is no other option but to go through Rajya Sabha, let labour and land laws be changed by the BJP ruled states wherever possible. Keep the public impression of BJP centered on mainly Nationalism, Governance, and small Hindu undercurrent. No overt dialog-bazzi.
The job of ABVP should be countering these organizations, ask the support of RSS wherever possible, spread more shakhas, and push them out state by state, Institute by Institute, like they have been pushed out of most states.
Let's hit them one by one, study these groups, closely, find out who are the players and what are their roles in these so called student organizations, find out the weak links eliminate them (politically or otherwise [specially in bengal]), weaken their recruitment and ability to move people, don't let them organize events or protest, pull them into confrontations repeatedly, even if they commit suicide, people will eventually forget as long as it's not having BJP name tag on it and the incidents remain small, remember most people don't read op-eds.
Most importantly, Right support should not lose hope, it will be a long battle, and it will be worth it, as it is the battle for the very soul of India, contrary to the way these assholes think, WE are the many, and They are the few. We will win, surely.