Hi,
I’ve finally solve the issue …
You need to add routing instance to context as this:
snmp-server context default instance [routing_instance_name] vrf default
What occurs in my case is I’ve name each instance with a different name: ospf, ospf-ipv6, bgp
I don’t know if you can have different routing protocols with same instance name for example “default”
So the only solution is create different context and v2 community mapped to each routing instance.
On NMS side (such PRTG) you need add various time same device with different SNMP community and proper OID to each one.