Refund of earnest money

Aftr my mom's demise, my dad filed a partition suit on behlf of me to get her share in their ancestral propty. There are five shares (of her 3 bros and 1 sis) in total, out of which 1 belongs to us. The case has been going on for abt 15 yrs now. In 2016, we decided to buy the other shares for a sum of Rs. 70,000,00 (70 lacs) as a compromise measure and entered into a sale agreement with them, giving earnest money of Rs.10,000,00 (2.5 lacs each to the 4 other shareholders). The agreement had the following clauses: 1. We're supposed to give the rest of the sale consideration, 60 lacs, within six months from the date of agreement as cheque. On that date itself, they should surrender the property and give possession to us. 2. Within the period of contract, if we became ready to give the rest of the sale consideration (60 lacs) to them on our own expense after making the ozhimuri document, and the opposite party fails to/refuses to accept the balance amount, then we have the right to get the deal completed by the district additional sub court. In such a condition, we have the right to deposit the balance amount in court ("Hence, it is decided so by both parties." - written like this) 3. If we fail to pay the balance amount within the period of contract and thus fail to get the registration done, then this contract and all the clauses will stand canceled and we won't have the right to get the registration done. 4. As stated above, to transfer the possession and ownership to us on the date of paying the balance amount to them, they must bring the original document and other important supplementary documents like encumbrance certificate etc. for the purpose of writing the new document. 5. If any kind of loans or dues are found on the property per those documents, they should make necessary arrangements to correct it and produce the original document afterwards. Aftr 4 months of the agreemnt date, we sent everyone notices stating that the money is ready and they can come with the original documents as decided on the agreement day. All four of them presented to our lawyer's office, not with the originals but photocopies of the stated documents. When we insisted to see the originals first, they refused and went back without finalizing things. We waited till the end of the sixth month and even waited for another week before making the court deposit of the balance sale consideration (60 lacs). They then started saying that we didn't pay on time, so its our fault. Now, they're saying that they want the land and can give back the advance amt. Our money has been lying idle without any interest in the court deposit for over 4 years cuz of their actions. So, we're agreeable to take it back. I know that until they return that advance 10 lacs, we have got charge on the property and that they can't sell it til then. But my question is, can we state a specific time for them to refund the advance amount? Is there any law/judgment on that? Thanks.