When ever air is turned on at thermostat inside air turns on, but outside unit all that happens is contactor is pulled in and that's all. Please help.

If the outside contactor pulls in then the 24 volt low voltage system is working to control the unit. You need to check the fuses and or circuit breakers in the outside disconnect and the inside electric panel to make sure the outside unit is getting 220/240 volts for operation.

OR

The power contacts are bad in the outside units contactor not allowing the 220/240 volts through.

If you have a multi meter and feel comfy using it, check for 240 at both sides of contactor while contactor is pulled in.