I´m so glad you´re helping this poor kitty! I would try and find out whether he belongs to anyone or not. Perhaps you could put a note up asking? If no one owns him, have you considered to take him yourself? Or find him another home? Because, if you start feeding him, you´ll have to continue as long as he lives. it would be cruel to stop, now that he has got used to it and waits for you every evening. A vet check also sounds like a very good idea!

If he is owned by someone, you should have a chat about how to take proper care of him.

I´m feeding a cat in our yard 3 evenings a week, other people in the building do it the rest of the week - summer, winter x-mas, holidays. If a cat has been used to living outside for many years, it can be very difficult to get him to live inside. In that case, you could perhaps get some more people together and make arrangements for feeding and sharing expenses for vet bills. If you find that it´s best he stays outside, you could build a house for him - we did that.

Hope you can use some of this advice! Best of luck!!