What is the eligibility to join the beta program?

eligibility is to not have a tactix model. otherwise, just sign up

The information is here - https://forums.garmin.com/beta-program/w/beta-wiki/112/how-to-enroll-for-public-beta-program

I was not able to find the part number in the Garmin site. I suspect it may not be the ROW set

Hence not sure if I could join beta. I guess I will only find out when I get the watch 

You don’t need to be concerned with the part number just the watch. If it’s on the list you should be good. Unless you have an APAC version.