Eviction of tenant.

An unregistered tenancy agreement on a Rs 10 stamp paper was made in 1994 in Kolkata (presumably under WBPT Act 1956) and which expired in 2000 (i.e. after WBPT Act 1997 was started but before the 2002 amendments). The agreement has such terms as "tenancy", " rent" but at the same time it says "tenant will only hold', "landlord can enter any time" etc. Rent was greater than 2K but less than 6.5K. and it was not renewed thereafter. But landlord has accepted rent in the meanwhile. Tenant is also not following many conditions in the original agreement including periodic increases of rent and doing small repair and construction without permission. Further tenanted area is now also required by landlord. Consequently landlord has recently stopped accepting the meagre same rent being given for a long time now without any increases. Therefore my questions are; 1. How to decide whether the aforesaid agreement is a lease or a license? 2. The landlord-tenant's present situation is governed by which Act if it is a lease? 3. What is the best way to evict this tenant considering agreement was a lease.