Change in MCOP Interest rate in Order

Sir, My brother died in Feb' 2002 in Road Motor accident, related MCOP case judgement came on 2008 with compensation of Rs.3,39,000/- with 9% compound interest; But Insurance company appealed in High court against order in the same year, But, in 2018 High court Verdict once again confirmed the lower Court order of compensation Rs.339000/- , BUT REVISION IN INTEREST RATE OF 7.5% COMPOUND INTEREST FROM PREVIOUS 9%. Sir, now my query is whether this revised Interest rate for onlycurrent year (present bank Repo rate period) or Throughout 16 years from the Date of case filling; My lawyer says for throughout 16 years, but another lawyer says " Bank interest rate will every year or half yearly or quarterly depending on RBI direction; But your amount was deposited in 2008 itself with 9% compound interest rate which was the prevailing bank rate in those period in Bank after Lower court Verdict; this amount accrued or multipled over the years with prevailing interest rates of each years; Your deposited amount is already multiplied, now you can't change the final figure; Only current year interest rate will be changed to 7.5% as per High court new order"...like that. Sir, I am very much confused now, which is correct? I spent a lot over the years with my time, work, patience & money, etc., If throughout the year is correct, is there any provision or option to appeal for regain previously ordered 9% interest rate? Is there any time limit for appealing? Should I appeal in High Court only or else can I appeal in Lower court itself where our previous order came? Please advice.. Thanks for your Noble support & Service. Regards, Maruthamani Coimbatore