You can have imli (Tamarind) occasionally for the sake of taste in your dishes. Imli is sour, making it Rajasik in nature. Rajasik foods induce feelings of anger, passion, and impatience in you. In the 17th chapter, Verse 9 of Bhagavad Gita, Lord Krishna says-
ahara rajasasyesta duhkha-sokamaya-pradah"
Foods that are too bitter, too sour, salty, pungent, dry and hot, are liked by people in the modes of passion. Such foods cause pain, distress, and disease.
Hence, it is best if you avoid tamarind totally.