1. "What's there!".
This is said in response to your thanking someone for something. "Thank you for the efforts you have taken for us." "What's there!" (Roughly, "it doesn't matter, don't mention it, it was no big deal."
2. "That's there."
This is said in agreement with some point that you have made. "BMTC is not doing enough to solve public transport issues in Bangalore...but they are also working under a lot of contraints, like bad roads." "That's there." (Roughly, "yes, I agree with you, the point you have made is valid."
I am totally used to both expressions...but they never fail to tickle me. They are there....