First just don't be afraid of being ragged.For avoiding ragging first change the way u think, don't be feeble otherwise u will be surely dominated by others. Be feindly with your seniors and be calm. If u get aggressive frequently than u may have to suffer. Although, ragging or bullying is a punishable offence but its also a way by which your seniors show right on you. Whenever asked something unacceptable try to be calm and resist it with respect.