When i logged onto osrs from my mobile it opened a new character other than my one on pc, while they are both the same account. Everyone told me that it should log onto the same character but my account has different accounts on pc and mobile. So please help.
Nick119 is right. OldSchool RuneScape which is available on mobile for everyone is another game that differs from the normal RuneScape 3 desktop version. You can access OldSchool with the OldSchool Client which you find when you click on OldSchool at the right corner at top of the RuneScape homepage and then click on play. There you get the option to download the OldSchool RuneScape client.
RuneScape 3 can be accessed via "Play now" on the normal RuneScape homepage (without clicking on "OldSchool" at the top of the page).