Is it permissible to take the amount allocated for tuition fees using unofficial receipts in order to compensate for a deficit in the basic salary?

If the amount is a grant from the state for specific purposes and you wish to spend it on something other than what it was designated for, along with forging receipts, then this is impermissible due to the deception and forgery involved, and because it violates the intent of the grantor. This is because a grant must be spent on what the grantor specified.