Property purchases from huf

I am purchasing a property from a HUF and the sale agreement executed This property was purchased by Karta before three month. Now the registry time coming on 3rd July so I ask Karta that at the time of registry all the members have to sign the registry but he denied for this and say that I am the Karta of HUF and I have all right to sale the HUF property and at the time of purchases i am the only party as Karta in registry. After some efforts to understand them they agree for consent letter form family members. Now i am in confusion that is it enough to get consent letter from HUF members or not. Need your Help regarding this.