Is there any grace period for a personal loan?

Usually, the creditors don't report it if you make the payments within 2-3 days time. But, that also depends on the creditor if it's not mentioned in the loan agreement.
So, it is always better to make the required payments within the time.

Check out the loan agreement. If there is a grace period on your loan, then it will be mentioned there. For instance, if the grace period on your personal loan is 15 days, then you won't be charged a late fee if you make payments during this time. It wouldn't be reported on credit report also.

Did you make any agreement? If yes, then the grace period should be mentioned there (If any). You can also ask the lender regarding it. It is advisable to ask about it before taking out the loan.

Check out the loan agreement carefully, the grace period will be mentioned there.