Hello B.I Meena,
For calculating your percentage of your 10th class.Firstly you should add marks of all the subject, after adding them you have devide the total by 6.Now the number you after this is the percentage of your's.Each subject may have different marks,you have to add marks of each and every subject which you have got and for getting the percentage you have to divide them by 6.You can get your percentage by doing this procedure.