DO WE HAVE TO PAY SERVICE TAX ON RENTAL OF PROPERTY?

we are a deemed limited company We have purchased a flat in Hebbal and have furnished it with furniture, fixtures and fittings. We have given it on a rent for a another limited company for 11 months agreement. We get a rental income of Rs 35000 per month. do we have to pay service tax on rental
of fully furnished flat to the government. We have not registered with service tax. Please clarify.