• Partition of ancestor property

Ancestor property has been divided in two parts among legal male heirs (1 & 2) with consent from female heirs (3 & 4) & agreement has been done 15 years back but not yet registered.   Now one of the legal male heir 1 has expired having two sons (5 & 6).  Two sons claim that the partition is not correct & need more property.  They are not ready to get property registered as per earlier agreement.

So what is the next step to get property registered? Whether property can be registered as per agreement without presence of legal heirs sons 1 ( 5 & 6) & with presence of legal heir 2?  Please advise. I am asking this questions on behalf of legal heir 2.