Family members in the case of Partition of land

I am kozhikode (calicut), Kerala and we have a common property, which measure 6.08 cents. The five family members belongs to the property are three sisters of my mother, one brother of my mother and my mother. In 2008 January 1st, my mother gave her 1/5 share of the property to me and she is still alive. One of the sister died in 2016 and her share will go to one of another sister with respect to deed prepared before her death. At present the property belongs to two sisters (aunts) and one brother (uncle) of my mother and myself and each will get 1.52 cents. My uncle is ready to sell his share, 1.52 cents to one of my aunt. An exchange of 0.15 cents from nearby property of one of my aunt with another aunt is also is planing to get road access to her adjacent property. As per Kerala registration rule issued on 24th July 2019, the stamp duty for Partition is 0.15% over value of the property shown in the document or minimum Rs.1000/- in the case of partition in between family members. In other case, it is 6% over the value of the property. Now the document writer is insisting us to purchase stamp paper at the rate 6%, because he says, in this partition a sale and an exchange of property is coming. Moreover I will not come under the meaning "family". So please clear our doubt and reply as soon as possible. Regards Satheesh G Nair