Pension of missing government servant

My maternal grandfather is missing since 2004 and the pension authority is now releasing the pension after the intervention of human rights commission. Sir I would like your help on these points. > 1: as my maternal grandfather was missing the pension for those seven yeras will be given as by calucating it as of my grandmother which is less or of my grandfather which is more. > 2: is there any provision through which we can demand interest on this amount for these 12 years. I will be very thankful if you provide me any knowledge on this matter. Thanks and regards Manish uniyal