1. Dementia is not "Lunancy"
2. Under the Contract Act, a Lunatic person is prohibited from making a contract.
IMP : Get a medical certificate from a psycatrist of a muncipal / Govt hospital that the patient is under treatment / or is suffering from Dementia and not from any other Lunatic disease.
3. Coerced or forceful tactics of obtaining Thumb Impression, is Cheating & Fraud.
4. application should be made to the District Registrar's office alongwith appropriate stamp duty paid documents and reasons should be specified.
5. The Registrar has statutory jurisdiction to depute a deputy registrar to visit the Persons home and take his signature / thumb impression on any documents that need to be registered with the Registrars office. A statutory service fee is levied for this purpose. Retain the application and the visit fee receipt, and the doctors medical certificate properly for life-long.
6. Make the agreement and a irrevocable POA seperately after paying the stamp duty. The deputy registrar will inspect and the dementia person can be assisted by the deputy registrar to put his Thumb impression on such documents. The documents will then be registered at the Registrar office under stamp and seal.
Meanwhile you may prefer to have the Father "WILL" registered in the above manner to give it a finality.
Two outsider witness will be required. 2-4 photographs of the owner & POA holder will be required.
The above document processed as above, is not challengable or disputable under the law.
Try to contact an Advocate who exclusively practices in Property disputes and get it down appropriately.
Keep Smiling .... Hemant Agarwal