Yes, women can wear a bra during Umrah, even while in the state of Ihram.
Wearing a bra does not violate any of the restrictions of Ihram for women. The primary restrictions for women in Ihram revolve around specific clothing items (like gloves or face coverings) and certain actions (like using perfumes with strong scents). A bra, worn for support and comfort, is perfectly acceptable.
There are no specific requirements for the type of bra to be worn during Umrah, but comfort is key. Since you will be performing physical activities such as walking and praying, choosing a comfortable and supportive bra is highly recommended. Consider a non-wired bra for extended comfort, especially during warmer weather.
In summary, wearing a bra during Umrah is permitted and is a matter of personal comfort and support.