Power supply to project board issue
I'm powering up the board using 12V,5A adapter. I have a 7805 regulator at the input side. I'm planning to run small submersible 5V pump(5V,200mA) which is also connected to the same regulator. is it OK?

Probably not.
That's 7 V drop you'll have in the regulator, and you're drawing 0.2 A; that makes 7 V · 0.2 A = 1.4 W of heat that you're producing in the regulator whenever your pump is running.
Depending on which variant of the LM7805 you're using, and how much cooling you add to that, this might either be on the edge of still working, or being so hot that your regulator gets damaged or stops working.
Really, nothing in your circuit uses 12 V – directly use a 5 V power supply would be my recommendation. If you were my neighbor, I'd just reach into my trashbag of old 5 V supplies and give you one. But you're not my neighbor (I think – else, come over for a coffee and say hello!), so you'd have to buy one (used or new), or find one that someone else threw away because the phone they used to charge with it no longer works.
If you really need to stick with the 12 V (I don't think so, honestly), you'll want to use a switch-mode step down (buck) converter to get from 12 V to 5 V. That doesn't get as hot.
By the way, there's no reason you'd have to use 5 V to drive your relay. You could just as well use a relay with a 12V-rated coil instead.