If the lease period is less than a year, then one may or may not get the lease papers registered.
If the lease period is more than one year, then it is mandatory to get the lease registered. An unregistered lease deed is void and courts do not enter into the merits of the deed. At the most, in such a situation, a lease not exceeding one year is presumed to be created. The conduct of the persons concerned should reflect the existence of lease, i.e. occupying the property, payment of rent etc.. In such a situation, where though one has paid rent for years together, but the aggrieved party cannot claim any benefit (like non-eviction from lease property). Despite the best intentions and conduct of the lessee, the courts refuse to accept the lease beyond one year.