Method:

1. Extracted the cloud part from band 6 (SWIR) 

2 Used this extracted cloud data to mask all the bands (2-7) to remove the clouded area.

3.Used the same cloud mask file to extract the cloud area from a cloudfree image. Now this image was being mosaiced bandwise.

Result;

1. Bands 5-7  is giving good result after mosaicking but bands 2-4 (blue, green and red) is not giving result. it is simply making the mosaicked cloud area either black or white.

How can this issue be solved?