Which sentence is correct ?
Each one of you must make up his mind.
Each one of you must make up your mind.
From the knowledge I have , Each is followed by his but since here we have one of you so will it will take your instead of his ?
Each one of you makes it clear that you are directly addressing a group of people. When directly addressing people, the possessive to use is your. Unless, that is, each person is being tasked with convincing a male third party of something, in which case his can be used. This context must already have been established for this usage though.
If you are not directly addressing people, but are instead reporting about a group of people, then you would not use you and your, you would instead use them and their or say "Each one must make up their mind" (without the them).
I would tend to steer clear of his/her in this situation unless it is made clear at the start of the sentence that the group is all male or all female, and even then I might still use their.
Each one of you must make up your mind. Is the correct sentence.
If you say the first then a question rises: Who's mind and how is each one of them going to make it up?