Great question. HDFC income guidelines based upon family size are based upon your situation when you purchase. You can get married later, you can have children later, and of course these things change family size, but they are after the fact of purchase. The income caps are only at the point of purchase. So yes, you can purchase when single, then get married and have a joint income that exceeds what it was at the point you were purchasing. It's no different than if you bought single with your current job and later landed a job that paid much more.
