Is it permissible for a person who works on the purchasing committee and refers bids to enter into a commercial tender and submit a bid, knowing that he is unaware of what others are submitting, and is his action in doing so halal or haram?

If your participation in the tender does not harm anyone, and there is no infringement on the rights of others, and you will not receive preferential treatment from the committee members, and the work conforms to the specifications, then there is no objection to it, provided that the law does not prohibit the participation of employees in the tenders committee.