Dear Bhargavi, that was a wise thought of you have to considered this. There are 2 things to it. Comfort and following the rules. The NEET Dress codr policy is in place so that there is no violation of anyone's religious practises while allowing fair and non malicious ways of appearing for the exam. If you have short hajr, you cannot tie it up and that is allowed. But on the other hand, if you have reasonable length of hair that can be tied up, it is good that you tie it up for 2 reasons. With technology developing beyond man's wildest imagination invigilators are right when they think candidates can hide devices anywhere. And you do not want to draw unnecessary attention just before an important exam. Secondly, the exam is in May and the weather is already hot. During the whole durstion of the exam your focus shouldnt be on pulling your hair back because it is too hot and humid. Its your oncr chance in the whole year to get you closer to your dream and you shouldnt let silly factors like untied hair distract you.