how can i check the chip i bought is fake or not

best way - buy from an authorised dealer.

There can be slight differences in the markings when the chips are made in different factories, but the picture on the top really look suspicious. The triangles in the As aren't aligned properly, I think they are fake. Personally I wouldn't use them.

You could check continuity between pins that should be connected internally, such as ground and supply pins. That should indicate if the chips were something else that has been remarked.