Power of Attorney in West Bengal

Please could an expert in West Bengal land law help? I own some land in WB jointly with my mother and two sisters (and some cousins who live in WB) - we all live in the U.K. but our mother is an Indian citizen. My mother is visiting India again shortly, and requires power of attorney from her three children to sell the land. My question is: what format should the document take? I have read an earlier forum thread on this site from three years ago. It suggests that we need to: 1. Visit a solicitor in the U.K. to sign the POA and have it notarised; 2. Visit the Indian consulate to have them verify (apositille?) the document; 3. My mother must then take the document to the relevant office in WB in order to pay stamp duty. Is this correct? Also, is there a standard format or wording for the POA? Many thanks, Sabuj Sarkar.