You can use either the official Tibia Client for 8.6 or any other 8.6 compatible client. Please check out otland.net or any other source of your trust to download OTClient, Tibia Client or any other.

 

TibiaClient Downloads (examples):

• OTLand OTClient 8.6 plus
• OT Serv List client download
• OTClient Github Releases

The server is based on Alkurius 8.6 from OTLand: [OTLand] Alkurius Global 8.6