I think what OP wants to ask is to survey what is the acceptable market rate currently so that he/she will not be shortchanged. I'm assuming the agreement hasn't been signed yet.

Anyway, the current acceptable rate is 8% per annum (daily basis) on the purchase price.

ie. if the purchase price is RM100,000.00 then the equation will end up something like that:-

[RM100,000.00 x 8% / 365] x days

*days is the number of days delay to be calculated from the date the vendor is obliged to deliver vacant possession of the property until you are in actual receipt of same.