affidavit for not demanding fixation arrears of previous service

sir i served in the university on adhoc basis in grades for 20 years ,thereafter absorbed in the same university through passing ordinance by the state govt, in 2008. then i filed case in rajasthan highcourt. court directed university and state govt. to give notional financial benefits upto 2008 and thereafter actual benefits.DB also supported my case, even special appeal filed by the university against me in Apex court has also been dismissed.under contempt petition filed by me in high court, the University and govt gave undertaking to comply the decision given by SB. Now University if ready to give the fixation benefit but demanding an affidavit on 100 rs NJ stamp in the form of undertaking that you will not demand the amount of arrear from us , till the govt provides the same ,were as govt in his communication with the university that he has to pay the same from its own resourse.once we give affidavit then can we say in the court that we did i pressure of fixation