Land Share of Basement ?

Hi, The question is w.r.t. free hold property located in Paschim Vihar, West Delhi. There are 3 owners: 1. First owner has single registered agreement of G.F. & Basement (Small) which says "Proportionate rights of the land underneath" (Sale deed done in 2005) 2. Second owner has registered agreement of F.F. with "undivided, indivisible, proportionate share in land rights out of the total land beneath the said property" 3. Third owner has registered agreement of S.F (with Roof/Terrace Rights) with "undivided, indivisible, proportionate share in land rights out of the total land beneath the said property" Now all three are entering into a collaboration with a reputed builder via partition deed wherein Builder will demolish and construct the property again (Basement, Stilt Parking, Upper G.F, F.F, S.F, T.F and Roof). Please suggest how should the land share be divided among the 4 parties considering all 3 existing parties would be getting same monetary benefits along with one floor each (G.F + Basement owner to get Upper G.F & Basement, F.F owner to get F.F itself and S.F (with roof) owner to get T.F (with roof) with builder taking S.F)