Does the approach temperature of a cooling tower affect chiller efficiency?

Yes, The greater the approach temperature the lesser is the efficiency of the chiller as the water will be supplied to the chiller at higher temperatures .

if approach is good it will increase efficiency of chiller good approach means less temperatures of entering water of water cool condensor.

I donot remember the fomula and relation of cooling water temperature with its efficiency but i do remember that ->Chillers efficiency increases with square of drop in cooling water temperature.

Yes.
Higher the approach lower is the chiller efficiency.
As per CTI5 deg F is the std approach for a cooling tower.
As the WBT drops approach increases for a selected cooling tower and the designed approach doesn't remain constant.

Agree with Mr.
Waleed, Cooling tower approach is the temp.
difference b/w ambient WB and leaving Cond.
water temp.
Cooling tower approach dT will be inversely proportional to Chiller efficiency.
However increasing the approach in the design stage would help to reduce the cooling tower size.