Index 2 copy shared by seller but unable to find the same online

We are looking into purchasing this property in Thane. The documents shared by the Seller are copies of the registered agreement with the stamp of the sub registrar. The index 2 was seen in the documents shared with us but when searching online we were somehow not able to locate the index number 2 from the 1st owner to the present owner but the index number 2 from the builder to the 2nd owner is accessible online. Hence we are a bit confused on how this could happen and whether there is any discrepancy with the property despite the name plate being there in the current owner's name in the society name plate board and on the door. The building is a little over 10 years old and the present owner seems to have completed the purchase in 2014. Need advice on whether there are chances of any discrepancy or document fraud because the index 2 is not accessible online of the sale between Owner 1 and the present Owner. Would like to know the reasons why the index is not accessible online in case the seller comes out clean with his documents