There is Delta and Y wiring connectivity is shown on nameplate of 3-Phase water pump,for which option i should go Delta or Y.what would be the effect if i make connection Delta instead of Y OR V.Versa

It depends only by the voltage level of your power supply.
For example: if your pump has a rated voltage of 400/690V 50Hz, you have to make a Delta connection if your power line is 400V; or you have to make a Y connection if your power line is 690V.

in AC motors, the starting current is huge and is 3 to 4 times of the normal current and can damage the motor. It is recommended to start the motor with star connection to decrease the starting current and then switch to delta to get to the higher speed.
Using this method , you can also increase the operational speed range of the AC motors.

Generally the AC Electrical drives connection depends on the connected load and fault level available at the power source. Moreover, if the load at starting is likely to be High and the Short current level of the source is reasonable, DELTA connection is recommended. otherwise a starting means to be adopted that includes Star/Delta configuration to reduce the staring current for a while (about 15s).
For pumps, type of pump, size of Motor ,,etc to be considered.
However,for small pumps direct on line (star) may be rquired, for other star/delta is required( Motor Start for 15s with star connection, thereafter to delta in running conditions).