I prefer Mann.
Mann name sounds so much powerful than Lord Hanumann. Suits Anirudh way more better than Hanumann. I am sure Imarti referred to him as Mann, but I do not see Babita referring him as such. Two ladies, and obviously different personalities. We do not know yet about Imarti's education etc. whereas Babita is shyly fitting the modern world, independent and capable of speaking in English etc.
I had hard time visualizing the closeness between Babita and Hanuman versus Imarti versus Mann.. Also, not forgetting now there is 8 year gap and one does get mature based on circumstances. I think their closeness will start with Babita accepting him. He already has. Also, I feel, even though she cooks for him, she becomes a mother when preaching him about alcohol etc. I do not know if men like that in a woman.
Lets see how the story folds with Imarti's (so called murder) past. Right now, Mann needs support from both of them, from what i see so far, it will come from Mini.