Do different jurisdictions have different specialities?
NCIS as an organisation is, per Wikipedia...
The United States Naval Criminal Investigative Service (NCIS) is the primary law enforcement agency of the U.S. Department of the Navy. Its primary function is to investigate criminal activities involving the U.S. Navy and U.S. Marine Corps, though its broad mandate includes national security, counterintelligence, counter-terrorism, cyber warfare, and the protection of U.S. naval assets worldwide.
It has offices in many locations both in the US, afloat and worldwide.
Each office will deal with the issues arising from it's area of responsibility in it's geographical location.
However...NCIS: Los Angeles concerns a special division of NCIS rather than a "standard" NCIS field office.
Again, from Wikipedia...
The series follows the exploits of the Los Angeles–based Office of Special Projects (OSP), an elite division of the Naval Criminal Investigative Service that specializes in undercover assignments.