You can download apps from the play store which allows blocking sites and applications for some time. So, when you are going to study you can do the above-mentioned things.

Another thing you can do is try giving your mobile to your mother or any family member and tell them not to give you your mobile till you will study. It will be the best thing for you.

Try to study from mobile if you are very much addicted. Try to find channels on YouTube which are good for NEET preparation or download applications for the play store for preparation.