Does the court have authority to correct their own previous judgement

my father has two wives i am first wife son.we are Hindu.after my father death we tried to get legal certificate from thalukoffice but they refused to issue certificateand they told us to appeal on court.on 2014 second wife and her lawyer came told us "we both together apply legal heir certificate on munsif court and they bring some papers in that both family members name were mentioned and not denote first wife or second wife so we signed in that papers".after that" her lawyer told us not come to court i will handle the case ".after some months we came to know we are cheated by them,second wife has got legal heir certificate in that she mentioned as first wife and my mother is second wife.so i filed petition to that same munsif court to correct the judgement but munsiffcourt judge ask our advocate to show authority to file this case because we are also plaintiff to previous case,and we arenot applied in 60days after judgement please helpus is court has authority to correct judgment.