1.mon, 2.ma 3.mes = my (respectively : the possession is 1. masculine 2, feminine 3. plural)
1.ton 2. ta 3. tes = your (respectively : the possession is 1. masculine 2, feminine 3. plural)
1. son 2. sa 3. ses = is/his/hers (respectively : the possession is 1. masculine 2, feminine 3. plural)
Le mien (mine the possession is a masculine word) la mienne (mine but possession is a feminine word) les miens (mine the possessions are plural)
The same goes on for le tien, la tienne, les tiens, le sien, la sienne, les siennes... You need to coordinate them with the thing you own.