routing both ipv6 and ipv4 in a tunnel

Dear all,

Hi

There is a situation that we want to make a tunnel between fortigate 1000c and mikrotik to route both ipv6 and ipv4.

There is an option called "config system ipv6-tunnel" and "config system sit-tunnel"

which one is suitable for our requirement?

 in sit-tunnel we use ipv4 to establish the tunnel and assign an ipv6 on the tunnel. can we use this for routing both ipv4 and ipv6?

Thanks