If you find it funny, laugh. If not, smile, or ignore it.
I think it's a self-deprecating joke. Not the kind where it targets a different race or culture.
If I'm an Indian and I make a quick funny remark about us Indians' accent when speaking in English, it's only a joke. Nobody is being targeted. If it makes you uncomfortable, you can just ignore that you heard it, or put on a decent smile. Else, you can join in the moment, relax a bit, laugh. ;)
On the other hand, if it's a native English speaker making jokes about Indians' accent, it may not go over well with everyone around.
An exception to this is if there's a brick wall behind and it's a standup comedian performing. People usually attend the show for unrestricted and uncensored comedy. And whoever is offended by such jokes can just not go there.
It should be noted that there's a difference between laughing with the people or at the people. If I'm joking about how clumsy I am and we're all laughing together, I'm okay with it. But if someone else is making fun of me, calling me a clutz, and laughing at me, then it's not fun for me. Good stand-up comedians know how to navigate through this considering the context and the mood of the audience.