I get the reram cell as below in magic. What is the blue area in the layout?

Blue area? You have metal1 crossing metal2 with a ReRAM device in the middle. It looks like you read the GDS of the device from the library, so you get the "TE" and "BE" ("top end" and "bottom end") pin labels in the ReRAM cell.

I have found reram in sky130B . So I can draw a rectangle and use paint reram command in magic to get one. But there is a doubt regarding taking connections. Is it like, from one side of reram I connect a metal 1 layer through via and and on the other side I connect metal2 through via? Please give suggestions.