In current situation, I think that may be a good idea. Regarding crowd, railways already have stats of how many students will go to which city from where, and acc to that stats, they ca run special trains. Regarding hooliganism, deal with it strongly. Rusticate the hooligans from exams for few years. Though this is easier said than done but something has to be done. Ek to vacancy nikalti nahi aur nikalti hai to aise logo ke chalte pura delay hota hai. August mein hona thha SSCCGL 2018, ab December se pehle hone se raha, due to malpractices in SSC CGL 2017.