Quantity discount

Is quantity discount given by the manufacturer is exempted in the hands of retailer?

ex. If me as a mobile shop vendor purchase 1000 nos of oppo mobile phone and I was able to sale the whole mobile within a month or two. Than the manufacturer giving me a discount on quantity basis and asking me to pay them only for 900 nos. Or what if they are giving other kind of quantity discount? Is any of them are exempted under GST