Typically, Tai Chi students wear anything they want. It is helpful to wear something loose and stretchy and to leave jewelry at home; however, the rest is often up to you.
The most common Tai Chi suit is a T-shirt and sweat pants. Spandex or body suits, although not prohibited, are not typically worn in Tai Chi. Also, longer dresses can make it more difficult for an instructor to see posture or leg placement.
If you go from the office to class di bring shoes to change into. Tai chi shoes need to be comfortable and supportive with a flexible sole and if you are a serious player then shoes designed for the purpose are always a good idea.
We will be happy to direct you to a martial arts supply store that sells the appropriate garb.