It sounds like you have the relationships backwards. If the entity receiving the service is paying you for it, they are the customer, not the supplier. The entity providing the service is the supplier. But this is not the way you first described things. You originally said, "I have receivable from my customer of Rs. 100,000 out of which Rs. 90,000 belongs to my supplier and Rs. 10,000 is my Income (Brokerage income).
Since two different entities are involved, you cannot put all related transactions on one form. You must raise a sales invoice to the customer (who receives the service) for Rs. 100,000 and a purchase invoice from the supplier (the service provider) for Rs. 90,000. This will properly record your revenue and your expenses.
The sales invoice can be a single line item, in which case your customer will not know how much represents your fee. And your broker’s fees will not be specifically tabulated in your Profit and loss statement. They will simply be included in net profit. Or, it can be two lines, one for the service cost and the other for the broker’s fee. This approach will give you more visibility on the sources of income.
The purchase invoices will not mention the broker’s fee. It will include only the charges from the supplier.