Recently had a new pond dug....drain tile is coming into the pond about 2 feet under what will be the water surface.

What problems am I looking at? Is my water level going to remain under that drain tile? Should it be plugged or keep it to help keep water level up.

Pong still has about 8 feet more of water to fill up before hitting the drain tile.

Also will water leak around the drain tile site coming into the pond?

That depends on the elevation of the drain tile once it is away from the pond. Think of a bathtub, you poke a straw through the side of the tub 2" below the water level and put the other end of the straw in a bucket of dirt..... If the bucket of dirt has the straw going into it above the high water level in the pond, then no water will leave the pond via the straw. If it's lower, then it will drain out to the straw level until the water level in the bucket is equal to the water level in the tub.

One solution is to create a small pool near the pond and terminate the tile there. A short tile could then be installed between the pool and the pond slightly above the pond surface water level. The pool would also serve as a settling pond in case the tile water runs brown during heavy rain.