Indira, I’m sorry but we cannot recommend specific brand names as we do not endorse any companies. However, I can give some general recommendations. Herb plants do not need much fertilizer. Often potting mixes have a long lasting fertilizer in them and you may not need any additional fertilizer for a few months. Check on the bag of whatever mix you used and see if it has fertilizer. Beyond this, you said you are looking for an organic fertilizer. You can pick any organic fertilizer in the store or garden center. Often thy will have recommendations for herbs on the package. If not follow the least amount of fertilizer recommended as herbs do best with less fertilizer. Sometimes if fertilizer is too generous it can make the herbs taste “off” and will not have the best flavor. For more information on the subject, the following link is for a publication on growing herbs in containers.

https://web.extension.illinois.edu/containergardening/herbveggie_herbs.cfm