Rate of interest and type of interestfor refund by builder to INVESTOR in the case of delay

Adjucating officer of rera give order to builder in my faviour to refund principal amount with interest.but interest rate is very less @12% simple interest only. But 1) in the agreement with builder .builder put the class of interest rate @21% in the case of delay payment by me.hance i alwas pay him on time. 2) i took housing loan by hdfc @10.25 on monthly payment basis (compouding interast) 3) since last 5 years increasr price of flate from 75L to 2.08 cr i.e on an average 55% per year. 5) to pay builder , bank instalment i took one housing loan And 4 home equity loans to repay interest regularly. 6) During last 5 years i pay more than 1.8 cr as interest by various bank housing loan account and 4 home equity loan accounts 7) project is delay more then 2 years and still 70 % work remaining 8) mp rera fix the rate of interest as per sbi landing rates.wich is 8% now and also giving only simple rate OF interest not monthly compunding as bank charges. 9) builder took PROJECTS loan @15.6% by hdfc 1 I want to know rera apelate authority is bound to gives only sbi landing interest rates on simple interast@12%/as per agreement @21% compounding/@15.6% builer is paying to hdfc for same project