visa for my brother's son

[ntr468]

My mom is currently in usa on a tourist visa. My dad is now planning to
visit us for about 3-weeks. Also, we were planning for my brother's son who
is 8-years old to come along with my dad. I am doubtful about the chances of
my brother's son getting the visa.
First of all, can my brother's son attend for visa interview along with my dad?
If so, what is the chance of obtaining visas for both of them?
Is it a good idea to attend for visa interview seperately? i appreciate
your advice and feedback.

[immihelp]

Yes, your nephew can apply with your dad.

Rest of the questions are quite subjective and there is no one accurate answer for that. Anything could happen.