If it were me, I would put it in a bigger pot. That should help it quite a bit. Eventually all the fronds will turn brown but new ones will grow in its place. Definitely start by repotting it.

I've had that yellowing from the centre out to the leaf extremities happen at hot times when there's a lack of water and soil is infertile. The repotting with fresh fertile soil as recommended would be best. In a pot and if it's in a courtyard the roots would be getting quite hot, especially compared to what it would be in the ground. Which part of India are you in?

Thank you both for the considered and thoughtful replies. I'll definately give the plant a new home in a bigger pot, and hope that it responds. It'd be a tragedy for this one to not pull through.
I'm in the state of Rajasthan, it's the hottest part of India. Since you've been so kind as to reply to this query, I was wondering if you could also visit my other problem and tell me what you think.
Once again, I deeply appreciate your taking out the time and putting in the thought to see what needs to be done.

Here is a link that might be useful: Ficus leaves turning pale and yellow!!

I've only been to Mumbai, it would be more humid than where you are. A lot of tropical houseplants come from a climate more like Mumbai's. I think you need to watch that humidity for your plants, and also watch out for overheating of the root system.

Thanks again for replying. First thing I'll try and do is get it into a bigger pot. Though finding one is going to be a real issue. I might need to have a barrel sawed in half and have holes cut in the base, because they normally don't make pots this big around here. And yes, Rajasthan is pretty much a desert (the Thar desert), so there is almost no humidity here. Mumbai being near the Arabian sea is very humid. I'll keep you posted about what happens when I've planted it in a bigger pot, though someone suggested the ficus I have which is loosing leaves is showing signs of a sulphur deficiency. Sulphur deficiency is rampant in Indian soils. It wouldn't be a bad idea to supplement with some Sulphur fertiliser, would it?
Thanks again.

Here is a link that might be useful: Sulphur deficiency in Indian soils

Being in a pot should make it quite easy to get the soil balance right. I had a look at that link and in it they suggest the correct ratio for fertiliser. You want to make sure you don't over do it though and end up with everything out of balance again. Using gypsum (calcium sulphate) is a good way to get calcium and sulphur into the soil without changing pH. But remember you are operating with small quantities.

Don't know what sort of climate you're in, but generally if it's a colder one then better to leave any fertilising until the warmer weather. Parlour Palms can take a very long time to grow big, and big for them is around head height. Also, they only grow "babies" from seed.