WANT TO GET leasehold land 999 years in grampacayat IN pune district

MY PARTY {lessee} DID 999YEARS LEASEHOLD AGREEMENT 30 YEARS BACK FROM OWNER N NOW THE PLOT IS VACANT FROM 30YEARS. NOW I WANT GET THE SAME LEASEHOLD PLOT FOR 999 YEARS FROM MY PARTY{lessee). the lessee is NOT empowered as per the contents of the lease deed to execute sub-lease.. do lessee have the rights to transfer his lease right to me and if yes than how ? CAN I LEGALLIY GET THAT LAND FROM MY PARTY (lessee) ON 999 YEARS ? CAN I CONTRUCT APARTMENT SCHEME ON THAT PLOT ? N WHAT DOCUMENTS WILL 1 Execute ? WITH FLAT BUYERS LATER on FOR SALE of FLATS WHAT documents TO BE DONE ? Can I do sale deed with flat buyers ?