Loan against property from individuals

Let us know first on what pretext you have given loan? Presumably with your explaination you have not give as one of a claimant I believe. In your instant case, the loan you have given to you father might be a helping or supportig loan to develop the property.

At the out-set clear your intention with your father the loan amount shall be treated as your contribution to property and in the event of sale/ partition you need some extra share. For this type of arrangment you need ot under goes for an MOU between you and your father.

To safeguard in the eventuality of the said property being alienated you can file objection the sub-registrar office and if you are more enough sound better obtain an injuctions against your father, brother or any third party.

Hope, I have clairifed your doubts.

You have no right, interest, claim or title in the self-acquired property of your father.

Other facts posted by you are of consequence.

However, it is advisable to consult a local prudent lawyer for proper appreciation of facts / documents, professional advise and necessary proceeding to protect your interest

Since you advanced money as money , you must have an agreement or sale against that amount. You can ask your father to partition the property and distribute shares among legal calimers. Or simply get a mortigage deed executed against proeprty in your name and make that registerd and keep lien on property in the revenue records. If your father cooperates you can execute and make any document. 

Your father is absolute owner of his self acquired property and he has every right to transfer it as per his wish.Merely giving loan to your father  do not make you co owner of propetty. so can't claim any right over property.