Do you think I can run GTA 5 on a Lenovo M90 SFF with Intel i5 Processor smoothly?

No, no way it will run. Those boxes have integrated video, not designed for gaming at all. Also, SFF cases have small, custom power supplies, which are too small to power any add-on video cards. Finally, SFF cases can usually only take low profile video cards, which are often low performance anyway.
Bottom line, that machine will never play GTA5 properly, if at all…

Not a prayer. Graphics far too weak

If it somehow runs, it would be an unplayable mess.

Save those $358 you would have spent on this system and put it towards a good PC. That PC would be OK for general home/office use but definitely not for gaming.

That computer should be on the ripoff alert list.

$175 would be a somewhat fair price.

No, there's no way it would run that game. You are at a further disadvantage since it's in a SFF case because it's too small to accommodate a decent graphics card. Please get a mini-tower or mATX sized tower if you want something that you could turn into a PC that can play games.

Yes