You may or may not be able to smoke in your unit, depending on the policy of the housing authority, property management company, or private landlord that manages your unit.
If you are a tenant in a Public Housing unit, HUD finalized a policy banning smoking on Public Housing premises in late 2016. More information about that ruling can be found here.
If you are a Section 8 Housing Choice Voucher tenant, that policy is determined by your landlord. The smoking policy should be identified on your lease.
In regards to other housing programs, some offices let its residents smoke, while others do not.
If an office or program does have a no-smoking policy, there may be designated smoking areas outside. Also, these housing offices will still rent to smoking tenants, it's just that they will be not be allowed to smoke on premise.
Contact the housing authority, property management company, or landlord that manages your unit to confirm the smoking policy. You can use the search bar at the top of this page to search for housing authority and apartment community contact information.