We have running
HSRP in production but its running on
version 1 now i want to change it to
version 2 so is there a way to do without any downtime or disturb live traffic?
I can't think of a way to achieve this within the limits of "same set of router interfaces of the same pair/group of routers".
HSRPv1 and v2 are:
a) incompatible and
b) mutually exclusive on one given (sub)interface of a router and
c) conflicting when implemented in parallel with the same standby ip addresses. That much, I assume, you already figured out.
In short: I don't think this is possible to achive without any influence on the live traffic.
Some trickery with temporay additional routers, secondary standby IP addresses and relying on the fact that a router sends a gratuitous ARP for the given standby address when it goes active might bring down the interruption to just a few seconds. However, that is neither pretty nor simple. To elaborate, more information about the given network situation would be needed.
Eventually, scheduling some downtime might be the best (non-)solution. After all downtime won't take longer than it takes HSRPv2 to go active, which in turn depends on the timers you configure.