Hi, you can try Zenith Yoga (http://www.yoga-hanoi.de/) which is located along Xuan Dieu (a few shops away from Veggies). UNIS also holds yoga classes available to public on a quarterly basis, as part of its community education program (http://www.unishanoi.org/pages/community/comed/comed_home.html). The classes have already started but you can join in the following session. Hope this helps!