Hello Ganesh Sir...
First of all sorry for late reply...
The group of Crows is known as Murder.
There are many reasons behind using this term mostly based on stories & also because Crows are scavengers, so it is believed that the presence of Crows is an Omen of Death...
This is how they got the name for there flock - MURDER...
Here it is my attempt to portray the Murder in concrete jungle...
And thanks for appreciation Sir...