Tetsujin is correct in that they can make any rules they like.
But much depends on whether you are a problem or not. Look around and observe the people flow. Work to stay out of the flow, out of the way. If it's busy, come back another day.
Failing that try the following:
- Use a monopod.
- Use a bean bag on top of something.
- Rig a rubber faced clamp with a screw that you can attach to a ball head. This allows you to use any upright post or tree as a camera support.
- Take someone with you who is an extroverted clown who can distract people from what you are doing.
- Practice using your body as a support. I found that with some practice I could consistently hand hold 1/8 of a second at 50 mm focal length. There are tricks that help.
a. Keep your elbows down.
b. Listen to your heartbeat. Shoot between beats.
c. Let out half your breath, stop breathing for the shot.
d. Put your feet as wide apart as your shoulders. Balance weight between heels and toes.
e. Lean your back against a wall, or your shoulder against a post or corner.
f. Sit down cross legged. Support your elbows on the fleshy part of your thighs.
f. Practice. Take 30-40 shots. Examine. What motion is left. Lather rinse repeat. If you start getting good shots, double the time.