age limit for super specialization exam in some institutes of india

I am a psychiatrist, practising for 5 years post my MD, Now after 5 to 6 years i want to upgrade my degree into DM by taking the competitive superspeciality exams of NIMHANS. This institution, a premier institute has put a age limit of 35 for the exam. My question is when all india entrance for neet superspeciality has no age limit, how can only few institutes have this criteria. How can i put a stay order for this exam or do something that this age limit is barred off. Thanks in advance