Sumon,
Welcome to IndiaWilds!

This is a nice first post. I like the spread out wings. It is nearly parallel to the sensor plane. I wish the light was better. A bit more sharpening would be good as well.

If you could have moved a little bit to the left, then the brown portion below the wing would have been minimised and would have further strengthened the image. Ofcourse, in poor light it is not always easy to notice. I would try to further reduce the highlights on the top leaf. Ovearll, I like this image.

Which camera and lens? Also, it would be good if you could share some details about this butterfly species. It would add to our collective knowledge.

Cheers,
Sabyasachi