So you have a VPS and you have a “MicroTik” router. What you specifically asking is VPN… 
Something like this, except you will be using Strongswan for IPSEC/IKE2 VPN protocol:
- http://forum.mikrotik.com/t/nordvpn-ipsec-ikev2-killswitch-for-ros6/144817/1
- http://forum.mikrotik.com/t/ipsec-ike2-with-certificates-vpn-server-guide-for-remote-access/149434/1
- http://forum.mikrotik.com/t/mikrotik-behind-nat-to-mikrotik-ipsec-ike2-with-certs-tunnel-eoip/144952/1
If you have “MicroTik” router running “RooterOS” 7, you should instead go with Wireguard as it is MUCH simpler to set it up.