The 4 of them discussed for a full 5 minutes on nominations at length naming Eijaz, Arshi, etc.
Watch the 1st January episode from 44.30– 49.34 and you'll be able to understand why BB nominated them.
Rahul and Nikki were there just before this discussion started, Nikki was siting with the 4 nominated contestants and RV was standing. He took away Nikki just before this started.
Was it just by chance or did he do it intentionally, I have no idea.
Anyway it's very clear why they were nominated.