Can i put a for sale sign on the house while tenants live there?

There may be other reasons why you can't put a for sale sign up, like zoning regulations, but  unless your lease says you can't do it, the fact that you have tenants is not an obstacle.  However, until and unless you either agree with your tenants to terminate their lease, or go through the court process to terminate the lease, you can only sell the house subject to the lease.  In other words, someone can buy the house, but they would still have to honor the lease.  If you represent to the buyer that you have full unencumbered title to the house, you may be committing fraud.