Ask him OSRS gold where you are able to get a symbol and he'll tell you that the symbol maker is in the 2nd floor of the palace (which will be below your flooring.) You will be allowed out and the Mogre will direct you to the symbol maker, not allowing you to move. You will speak to the Yarg, the emblem maker and he will ask you what symbol you want. You will be able to choose between Lannar: The Mogres of Weaponry and the Color Yellow, Lu'tog: The Mogres of Poison, Combat and the Color Red, Narran: The Mogres of Peace, Agility along with the color Blue and Yun'lar: The Mogres of Defence along with the Color Green.
He will then make you a symbol of the region you choose. Wear the symbol and you'll have the ability to pass in your region from the palace. To identify what region you belong to, simply choose the door of the colour. If you are not sporting the emblem or you're sporting the symbol but you do not belong to the area, the guards will stop you. You cannot un-equip your symbol while in your area. Your symbol will replace whatever is in your necklace slot.
Quest complete! Rewards: 7,000 magical XP, 12,000 strength and assault XP and access to Mogrin by talking to Captain Murk to sail you ! (Should you lose your emblem, talk to a guard outside of Mogrin to get one or if you lose your orb, talk to Tarren to get it back.)
Your region will have more of whatever your area believes in, so if you are in the Yun'lar region, it will have more complex defence and have more defenses or armor to buy from the mogre traders and will have mogre armor, even in Lannar you'll have mogre weapons and also have more weapons to purchase from dealers, Lu'tog will have mogre toxin (a poison that can hit around 13) and more poisoned weapons and Narran will have an under-water agility program and special mogre suits that will increase buy RuneScape gold your chance in agility (you won't neglect an obstacle as much.)