Hindu Succession Act

Want clarrification on Hindu Succession Act

One person died he does not have legal heir in Class 1

then in class 2  --- 1 --- not alive

then in class 2 -- 2 --   he has 2 brother 1 sister 1 brother died long back 

Now my question is whether 1 brother who has died his children has any right in deceased 

or children of deceased right start only if all brothers and sister died