Bombay (India) is now Mumbai (India)
LC still authorizes use of Bombay (India) as a corporate name heading. However Bombay (India) IS NOT VALID FOR USE AS A SUBJECT! When cataloguing a work ‘about’ use Mumbai (India) The city’s name was officially changed in 1996.
Gee…. I sure miss those old Cataloging Service Bulletins! I would have amended our database way before now…
There are still some Institutions with resources that were published when Mumbai was still called Bombay………
As with many subject headings YOUR institution will have to decide whether to use both headings with SEE ALSO references, or, migrate all the works to the new heading. It is a choice you will have to make taking in consideration what will best serve YOUR patrons.