Is it permissible to take a commission from an engineering firm in exchange for helping them submit a bid for a tender based on a study I conducted?

There is no impediment to taking a commission for the effort expended in studying prices and mediating for the office, provided that this is free from deception, fraud, and the usurpation of others' rights. The original principle is that the compensation should be a known amount, not a percentage of the project, due to the uncertainty of the wage when a percentage is stipulated. This is the view of the majority of jurists, while some Hanbalis permitted the wage to be a percentage of the profit.