Documens for markup -civil partition suit

hello, in a partition suit case for ancestral property filed by a HINDU family in banglore that is 70 yrs old property,what happens if both the plaint and defendant does not have the parent documents and both tend to claim it as missing or not available and there is no interference from any other third party or any such claim on this property . We are on the plaint side. both the plaint and defendants agrees the facts in the plaint on the property being ancestral in nature though and asks for their respective partition with other prayers. how will the DOCUMENT MARKUP stage go in this case..will the court gets it from the concerned department/appoints a commissioners /should the plaint take effort to gather such documents?