hi Baheej
i take it that you have given your supplier a drawing of the basic shaft but what he is requiring is the information to cut the spline. you can't give him just 15T 8/16 this is not enough info to work with, he needs to now the Table Number, table 10 is Flat root side fit,table 21 is Major dia fit,table 30 is Fillet root, these are all 30pa, table 44 Fillet root has a pa of 37.5, then you have to tell him which Class you require 4-5-6-7, table 21 has only got one class and that is class 5, the spline form is involute for all of these splines. with this info any gear suppier should be able to cut your splines, he should not need a drawing of the profile.