I don't think so there is any property to set the max limit. However, Text box and Text area have it.

You may use javascript to check the length in the rich text box.

Thanks.

Do you have a javascript code for this?

Hi 

Currently this is not possible on K2 however, you can log this as a Feature on ideas.k2.com, the more votes on the feature the higher the likelyhood of implementation on the product.

Please also add as much details as you and examples for use.

Kind regards