How to connect two Router from different IP range?

rayhan.engineer

Prominent
Nov 9, 2017
2
0
510
I'm connected from a local ISP and my friend connected from another local ISP. But both ISP under a main ISP! That's mean me and my friend basically under a main ISP but in a different IP range. So is there any way to connect each other??
 
MERGED QUESTION
Question from rayhan.engineer : "How to connect two Router from different IP range?"