The reporting time which is written on the rules and regulations is the starting time for the entry in the exam hall .
They fixed the reporting time 1or 1.5 hours early before the exam so that there will be no crowd and Huss at the time of exam.you can enter in exam hall before exam time and after reporting time.
Any other query always welcome
So good luck

Hiii

Since you have not mentioned about the exam you are talking about i can not specify about a particular exam.
In general it is compulsory that you reach exam hall before time so that you do not face any problem.
Suppose the reporting time is 10 am you have to make sure that by 10 you are inside the exam center so that you dont face any issue during security check, frisking etc.

Thanks!