Unfortunately, there is no special function as of now that calculates multivariable limits directly.
However, there are a number of ways to investigate the limiting behaviour along a specific one - dimensional "path". For eg:
syms x y t f(x,y)
f(x,y) = x^3 * y / (x^6 + y^2);
This gives answer as 0. But along "y = x^3", we get:
So clearly the limit doesnot exists. You can also use limit function in a nested manner to calculate repeated limits as such:
If both limits in (i) and (ii) exists and are NOT equal, then the double - limit does not exist. Of course, these workflows may not answer your query perfectly.
So, If you have a specific function that you are working on, you can post it as a reply to my answer. I will try to help you out, else, you can also post it as a separate question to reach a wider audience. Thanks!