#!/bin/bash
s="/iil/some/path/data/file1
iil/some/path/log/file2
/iil/some/path/BinDir1/file3
iil/some/path/BinDir2/file4
iil/log/file1"
perl -pe 's,^/?iil/(?:.*?/)?(data|log|BinDir\d+),/$1,' <<< "$s"
IyEvYmluL2Jhc2gKcz0iL2lpbC9zb21lL3BhdGgvZGF0YS9maWxlMQppaWwvc29tZS9wYXRoL2xvZy9maWxlMgovaWlsL3NvbWUvcGF0aC9CaW5EaXIxL2ZpbGUzCmlpbC9zb21lL3BhdGgvQmluRGlyMi9maWxlNAppaWwvbG9nL2ZpbGUxIgpwZXJsIC1wZSAncyxeLz9paWwvKD86Lio/Lyk/KGRhdGF8bG9nfEJpbkRpclxkKyksLyQxLCcgPDw8ICIkcyI=