Here3 gps module as base

Hardware CAN Devices
1

Can we use a here3 gps module with rtk capability as base station instead of here+ base?

2

Yes, you can. But how are you planning to connect it?

To the FC? No problem.
To a PC? A little more complicated.

3

I have two of these here3 module. One will go on copter. Another one i want to configure as base for rtk. Can i use one more fc and connect to mission planner to send rtcm data to copter? Or any other method to get rtcm data.

4

Try this instead (likely the cheapest fixed base option):

There are much better modules out there, but they cost 3 times more.

You could also try a local NTRIP source. Look at rtk2go or a state run CORS service.