I believe that you are looking for a specific dermatologist in kolkata..And this question of yours was assigned to me (in Mumbai). You could try using the direct consult to get in touch with the dermatologist you prefer. As for your concern, acne is completely treatable . So don't get frustrated . Visit the dermatologist you intend on visiting to start treatment.
Next Steps
do read this article before you visit : http://www.skinmatra.com/single-post/2016/07/03/Skin-Troubles-Here-is-WHAT-NOT-TO-DO
Health Tips
read this article as well . it might give you some insight : http://www.skinmatra.com/single-post/2016/09/17/Listen-to-your-skin-talk-Here-is-how