IPv6 Route

I have a sit interface on RouterOS and have a routed /48 I use for LAN. (tunnelbroker)

HE_endpoint —(sit1)RouterOS(LAN)—(f0/0)Cisco1(f0/1)—(f0/0)Cisco2

prefix63:1::/64 between RouterOS and Cisco1(f0/0)
prefix63:2::/64 between Cisco1 and Cisco2(f0/1)

Everything works on Cisco1
Cisco2 can ping Cisco1’s f0/0 interface(prefix63:1::/64), but not anything beyond that.

I added an ipv6 route on RouterOS prefix63:2::/64 to LAN, but still Cisco2 can’t ping RouterOS. Cisco1 is correctly forwarding packets to f0/0 interface but RouterOS seems to drop all those packets/response them out of sit1 instead of LAN.

Any idea on how to troubleshoot?
Thanks

show us your ipv6 routing table