Hi can i print a picture of a rabbi on a tshirt?

ב"ה Shalom There are a few issues to address in your question. First of all it has become accepted according to Halacha one may photograph a person. (שו"ת יחווה דעת דעת חלק ג סימן סג ) Secondly, the purpose of the picture should be to promote respect and may not in any way cause embarrassment or anguish to the person who is photographed. If the person is alive he may not want his picture in public and therefore you need his permission. Since we must be careful in causing anguish to others you may want to ask yourself if you would like your picture to appear so. (עמק המשפט ח"ד עמ' נ, ועמ' תרכז.) If you abide to the above guidelines it should be okay, however there may be those who will be more sensitive to the picture of a Rabbi in such a manner. Mo'adim Le'simcha