I have two routers (R1 and R2) in redundancy running HSRP (in the LAN segment) these routers connects to other
two routers (RA and RB, out of the LAN segment) each. So my question is if there is some command that can help me in
keeping track in RA and RB about the status of the interfaces running HSRP in R1 and R2??
Any help I'll be useful
Perhaps the easiest way for RA and RB to "know" of the LAN interface status of R1 and R2 is to run a dynamic routing protocol between the routers and advertise the LAN segment. (This has nothing to do with HSRP, which makes sense since HSRP provides a virtual gateway outbound but your question is tracking reachability from other outside routers, not local LAN hosts.)
Another way, if the platform is new enough, is to track the R1 and R2 LAN interface on RA and RB using IP SLA. This method, I recall, allows you to manipulate static routes on RA and RB pointing to R1 and R2. See http://www.cisco.com/en/US/docs/ios/12_3/12_3x/12_3xe/feature/guide/dbackupx.html for some more information on this technique.