Is it possible to get a six pack in 3 months?

No without injuring . This is time consuming & will need a long time to build.
Maybe, maybe not. Depending on where you start-out. If you are really obese, 3 months is not adequate time to safely lose the weight and at same time gain sufficient muscle mass to show the 6-pack ab. If you are average wt--see picture, and you eat healthy, exercise properly, better with a trainer, 6-pack is very possible. Some actually get that in less time. Consult a nutritionist and a trainer. Good luck.