how many routers is same ISIS process

Hi jahangirgp,
As far as I know, the number of routers that can be configured in an IS-IS process is not limited, but the number of routes on a router is limited. The number of routes advertised by all routers in an IS-IS process cannot exceed the maximum number of routes supported by a single router.

Hi 

You can use display isis spf-tree and display isis spf-tree statistics command to check the router numbers of the same process.