What is the maximum permissible duration for a lease contract, given that a permanent lease contract is invalid?

For the validity of a lease, the duration must be known. There is no maximum limit for the duration of a lease, so it is valid no matter how long it is, provided that the leased item is expected to remain. If it is leased for a period in which the leased item is predominantly expected not to remain, then the lease is invalid. If the leased item collapses before the end of the period, the lease is terminated.