How much Percentage of Profit you should put for the Order while quoting to the purchaser ?

It depends on the product and also may vary from product to product. For example , if your product is paint.  

Lets calculate the basics : Material cost ( The DP is easily given by company to its dealer)

Calculate its coverage area per litre, accordingly ( price /per sqm = rate per sqm ) practical basis not theoritical base.

Add ; Overheads - It contains freight to be occurred for transportation from Ex to godown (3%)+ Labour charges - loading/unloading (actuals)+ Sales tax extra (14%)+ Margin ( may be from5 % to25 % of the dp value).

It may land from15 % to25 %.