Since you are not the title holder to the property, even otherwise you cannot execute the registered sale deed in favor of the prospective buyer.

But as you entered into a sale agreement with the builder, a tripartite agreement with the builder is imminent,

However as you are not physically present you can authorise your father to sign the agreement on your behalf and for this he can have a notarised POA deed, and as the tripartite agreement would be executed on an unregistered document, the power of attorney deed also need not be executed by a registered document.

For getting the format of the POA deed, you can engage the services of any advocate of this forum or outside.

An attestation by a local notary public of your country of residence would be sufficient to attest the POA deed.

Execute specific power of attorney on favour of your father 

2) it should be attested before Indian consulate 

3) on basis of POA father can sign assignment deed 

4) father will have to be personally present before sub registrar 

1. GPA in your father's favour should authorise him to execute the Assignment Agreement on your behalf.

2.  GPA, after your signature in USA, has to be countersigned by Notary/the GPA has to be got attested by the Indian Consulate.

3.  After your father receives the GPA, he has to get it adjudicated in the jurisdictional District Registrar's Office in Bangalore.

4.  In case you desire to take my professional service for preparing GPA/Adjudication, etc., you can contact me through Kanoon.com

On basis of format provided by builder sign and get it attested before Indian consulate 

2) your father presence is necessary during registration 

If the flat is not registered on your name then how builder is performing tripartite agreement?

Ask builder to refund or make payment to you according to your demand or any specific amount to complete the transaction and builder can directly sell flat to new buyer.

If builder is performing tripartite agreement means Agreement to sale trans and has been done and register in the SRO office. Kindly check in detail with builder first 

- You can execute a POA in your fathers name for the said work done on your behalf 

- This POA should be notarized as per rule of US , and attested from the consulate of India. 

- Further, your father can signed the triparate agreement on your behalf , and there may be his requirement at the time of executing the sale deed as a witness but not mandatory. 

Q-1.

Since property is not registered in your name so you are not recorded owner of the property. Assignment of property shall be carried by builder at its own level. Your father being your attorney can complete formalities of assignment. On your assignment builder shall execute sale deed in favour of prospective father and for this purpose your father's presence is not required. 

Q-2. 

1. In case of assignment, since you are not a recorded owner it would be builder who shall execute sale deed. GPA is required to be properly stamped with registrar of stamping of revenue department.

2. For transfer of loan, paper formalities shall be required to be completed which your father can complete. 

3. Yes, being GPA holder your father is required to complete formalities of assignment. GPA is required to be properly notarised by Notary of Indian embassy and shall be required to be stamped in India. 

1.  Yes he should be present as a consenting witness.

2. He is right.

3. One GPA deed would be sufficient.

No you don’t require another gpa

Dear client, 

Granting a Power of Attorney (POA) to your father would allow him to act on your behalf in various matters, including signing documents related to the property transaction. However, it's important to note that the specific powers granted through the POA need to be carefully defined. In your case, if the assignment process involves signing documents related to the sale of the property, it's crucial to ensure that the powers granted in the POA explicitly cover such actions.

Regarding the registration process, it's generally required for the parties involved in the property transaction (buyer, seller, builder, etc.) to be present or represented during the registration at the registrar's office. Your father, as the holder of the POA, may represent you during the registration process. It's advisable to check the specific requirements and procedures with a legal professional or consult the local registrar office for accurate information.

Regarding the format of the GPA, it's advisable to consult with a legal professional who can provide you with the appropriate format based on your specific requirements and jurisdiction. They can also guide you on whether the GPA needs to be attested by the Indian Consulate in the USA, as this may vary depending on the circumstances and jurisdiction.

As for your additional questions:

It's possible that your father may need to be present as a witness during the registration process, but the specific requirements may vary based on local regulations. It's advisable to consult with a legal professional or the registrar office for accurate information.

If the lender (LICHFL) has informed you that they do not require a specific GPA format, but a general GPA is required by your father, you should consult with a legal professional to ensure that the GPA covers all necessary aspects and provides the required authority to your father.

If the builder (Prestige) has provided a specific POA draft for the assignment process, it's advisable to review the draft carefully and consult with a legal professional to ensure it aligns with your requirements and covers all necessary aspects. Depending on the specific terms and conditions of the builder's draft, you may or may not need an additional GPA.