can help... ?

[hyuga94]

anyone can teach increase drop rate ....

[haxorico]

Unlike many things, there (usually) isnt a specific line you can find that just says "Drop Rate Chance 100" and you change that around. In most maps it is usually in the coding (war3map.j) and you will need to learn jass to spot each and every item drop characteristics and how to change them, FOR EVERY MAP.
So we can't give you the global way of changing a drop rate. You need to learn jass in order to do so.