power of attorney holder seeking to carry out a land transaction will have to provide documentary evidence to the sub-registrar to prove that the principal, the person who issued the power of attorney, is alive. The principal has to obtain a "live" certificate with his photograph affixed to it from a registered Medical practitioner or gazetted officer and is valid for 30 days 

2) if land owner is refusing to give life certificate seek court orders to direct land owners to give life certificate 

The law is clear life certificate is must to prove that principal is still alive 

You can file complaint against landowners before RERA for failure to issue life certificate 

you can obtain court orders to direct land owners to issue life certificate 

Yes you can get clarity from the registrar. Nclt will entertain cases against companies only

you can sue the said persons claim  damages for  breach of contract 

What is the need of LC when you have POA. Let the POA holder should challenge the UDS registration. At least you should submit LC of rest owners and file suit of specific performance against rest two. They are bound to honor JDA.

Instead of LC submit declaration in the form of affidavit/bond that both owners are alive and POA is genuine and for any false information, you shall stand liable.

NO, writ, NCLT, RERA, C F but specific performance suit. 

The POA agent can issue a legal notice to the reluctant principals directing them to furnish the life certificate which is a condition of the POA executed by them jointly along with the other principals or to face legal problem through court of law while the litigation costs shall become  their liability. 

Registrar of the department will not be of any help to you in this matter, he would stick to his rules and regulations in this regard.

RERA cannot interfere in this internal problems, you may have to solve the problem yourself by legal means.

You have been misguided about this that NCLT or consumer forum cannot, again, come to your rescue due to the internal matters between you both.

The proper legal action is to take steps to issue  a legal notice and then approach court for a similar direction  on this instead of filling a writ petition.

You have remedy in the lower court itself hence there is no necessity for approaching high court with a writ petition.

1. As per the information mentioned in the present query, which is very limited, makes it clear that there has been issue of denial of some demands as per law.
2. Yes, you can very well get the remedy, but which way would be more appropriate, will have to decide after getting some more information about the matter.
3. As whether it is against government authority or against some group of people, so that can decide precisely as to go for Writ or Civil Suit.