should I quit an MNC job and work in a startup

All depends on what are your goals.

1. How much money do you want to earn now? And in 5/10 years?
2. What role would you like to have in 5 or 10 years?
3. Will that role allow you to earn that money? If not how cold you cope with that?

As for start-up they usually pay less. For sure you can learn more, but i suggest you to choose the start-up to work for based on the technology they use (is it some exotic framework nobody knows? -No thanks) and the success chances of the company (which IMHO are closely related to their ability to offer fair working conditions, nobody likes to be exploited to allow others to become rich).

My final advice is to start looking around, keeping your current job. If you find something worth it, change :)

I would suggest that, rather than leaving your day job and joining a start up, why don't you try freelancing. You can work on any technology that you like and can work as per your schedule. I am working in one of the big IT players o India, but also doing freelancing on sites like odesk.com or elance.com

I am freelancing for last 1 year and now seriously enjoying the experience. Let me know, if you are interested in freelancing, I can help you wit my experience.

MNC / Start-up / BS. What advantage does one have when working for a large corporation vis-a-vis a small one? In my experience, none. My most cherished days on job have been with a start-up, worked hard but had fun.

But start-ups make u slog. If u have been doing ur vb6 for a long time now, u may not enjoy 18 hour days every day.

My advise: Economy sucks. So keep the paycheck. If u want challenge, sign-up on Elance for some nice work. I hear its intoxicating. And if u r good, u may make some Cadburys too.

If you don't enjoy the work, aren't learning and are not having fun then it's time to do something else. Life is too short to maintain old crappy VB6 applications when there is a world of Ruby, Rails, Python, Node.js and all kinds of great things out there!

I'm not sure about the start up culture in India. I'm sure there are lots of small consulting companies that would give you the opportunity to work on more rewarding projects.

Or - get together with some buddies and create your own startup in the evenings and keep your day job to fund it. Quit once you have some money coming in.

There is no point of doing a job which you don't enjoy doing. It is good if you switch to some another job.

Regarding startup, I would suggest them only if you are willing to work hard, not concern about money and keen to learn new things at a rapid pace because as much I know about startups in India, they don't pay you big, make you to work hard and gives you more responsibility hence the scope to learn is also more.

Now its upto you to decide that whether you are willing to work that hard at less pay. Ofcourse working for a startup do counts a lot in future.

As per me, if you are relatively new to industry(fresher or 1 or 2 years of experience) I would definitely suggest to work for a startup as this is the time to learn as much as possible and since you might not having much responsibilities(from family point of view) so even money would not be a big concern to you.