It is not allowed to pray sitting, you must pray the fardh standing up. You can ask for permission to pray, if it’s not given you can pray after the exam if the time for the prayer did not expire before reaching your home. If you finished exam after the time has expired, combine it with Asr.

I wanted to know how I can pray zuhar prayers when I am in the exam centre. The exam centre is really small. so i wont have a separate vacant place to pray.And by the time i finish my exam and reach home it will already be asar time. I dont know in which direction i will be seated… Is it still ok to pray with ishara/ imagine each step aand recite duas in my heart? I am really scared about this exam..and have written it a couple of times and wasnt able to get through, Could you advice dua or namaaz, which will help me make dua to clear the exam. .