Amitabh Bachchan says "Paa" was crucial for his production company AB Corp and says son Abhishek has done a remarkable job as a producer by wrapping up the film within a Rs.15 crore (Rs.150 million) budget.

"Any film that a producer makes is crucial for him financially. And we completely recognise that. We can only hope that 'Paa' does well. This time Abhishek has managed all the production hassles and I am glad he has done it with a high level of maturity, " Amitabh told in an interview on phone from Mumbai.

"We had set out to make the film within an estimated budget of Rs.15 crore and Abhishek managed it in Rs.14.75 crore. This, in times when movie budgets are soaring to Rs. 50 crore.

"I think he has done a remarkable job. I give huge credit to him for making the film without compromising on the quality or the shooting locations. God willing, it will pay off well, " he said.

The real life father-son duo star in reverse roles in the film.

Amitabh says he was "quite well-behaved and obedient" on the sets unlike the "troublesome child" he was called by Abhishek who plays his father.

"Abhishek must have been fooling around when he said I was a troublesome kid. In fact, I was quite a well-behaved and obedient child (on the sets). I followed all instructions of the script and did as much mischief as the script and director Balki required from me. It was all in good fun, " Amitabh said.

In "Paa", Amitabh will be seen as Auro, a 13-year-old suffering from progeria, a rare condition which causes premature ageing among children. While Abhishek plays his dad, Vidya Balan essays the role of his mother.

Amitabh, 67, had to wear over eight pieces of specially crafted clay pieces designed by international make-up artist Stephan Dupuis for his role and says he was pampered well during the entire process.

"I was quite pampered on the sets. Actually they (unit members) were more worried about the makeup as it was very tedious. I used to have a lot of problem in breathing, eating and used to feel itchy - but everyone was extremely courteous.

"I couldn't eat properly, couldn't speak and liquid supplies were given to me using straws. Everyone was quite nice to me and pampered me, " he said.

But isn't he pampered much at home as well?

"Well! Of course, I am. But for 'Paa', I was really pampered like a kid, " he quipped.

Asked about the experience of playing his son's son in the film, Amitabh said: "It was fine. It wasn't tough. Actually, once you decide that this is a role you have to play in a film, the father-son relationship takes a backseat.

"We just played our parts. For an actor, I think it's all about catching the right attitude of his character and that's what we have both tried to do."

Amitabh is all praise for Abhishek's acting skills.

"I think Abhishek is maturing with each film. He really suited the role he has played in 'Paa' and I must say he has done a marvellous job."

Amitabh is being lauded by film critics and industry members for his portrayal of Auro. Many have called it "awesome", "amazing" and his "best performance till date". But Amitabh said humbly: "I'd rather wait for public opinion."

After "Paa", which is releasing Dec 4, Amitabh will be seen in Ram Gopal Varma's "Rann" and Leena Yadav's "Teen Patti".

As of now, he can be seen as a host on reality show "Bigg Boss 3", which airs on the channel Colors.