Power of attorney for selling my land

Hi, I have few questions on my Land in Bihar: 1) My father previously taken a notary power of attorney from my relative. Can i use this in any case to sell my land or it has to be register power of attoney only. 2) In case i have to take registered power of attorney, what documents and format is required for this. 3) Since my relative are now staying in Noida and my land being in another state, can i take registered POA at Noida and being valid to be used in another state. 4) Is this registered POA has to be done at registrar office only ? My relative is very old and could not come to registrar office so is there any way registrar office sends some officials with us to our relative home to make registered POA. 5) Can a registered POA be given to non blood relation (friend, Mama, Uncle) or it can be given to only blood relation(i.e. brother, sister). 6) What is the validity period of registered POA.i.e. timeline in which a registered POA be registered.