The landlord conditions that there should not be committed a forbidden act in the leased building
It is not permissible to let them install satellite dishes because their installment and use will ease the availability of prohibited watching. Also, it is not permissible for a Muslim to abandon congregational Salah. If some of those whom you have rented an apartment neglect congregational Salah, you have first to show your disapproval and to advise them. If they do not comply, you will have to inform the competent authority (Part No. 11; Page No. 165) to put a stop to the problem. You have the right to stipulate at the time of contract signing that the tenants must not fail to attend congregational Salah nor to install a satellite dish. Whenever they breaches the terms of the contract, you will have the right to ask them to either evacuate the rented apartment or to remove the satellite dish and to keep steadfast in performing congregational Salah and Jumu`ah (Friday) Prayer in the Masjid. Allah (Glorified and Exalted be He) says:
Help you one another in Al-Birr and At-Taqwâ (virtue, righteousness and piety); but do not help one another in sin and transgression. And fear Allâh. Verily, Allâh is Severe in punishment.
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.