No. If the tenant has failed to pay you rent for the past six months, you cannot legally lien the tenant's possessions. If you do, you could very well find yourself subject to a lawsuit from the tenant.If you have not been paid for the time period you have written about, your options are as follows:1. serve the tensnt with a 3 day notice to pay or quit. If not complied with, your recourse is to file an unlawful detainer action.2. serve the tenant with a 30 day notice of termination. Assuming the tenant vacates, you then have the option to sue the tenant for the amount owed.3. try and work out a payment arrangement with the tenant.4. do nothing and let the tenant continue taking advantage of you.I suggest that you consult with a landlord tenant attorney about your situation.