I am close to 50 and have not been able to save anything significant for my retirement. I don't plan to retire at 60 and would be hopefully working till 65 or 70 years. But how should I start planning for my retirement now?
If you have not started yet, then you should start now, as beginning itself is a big challenge. In your case, save whatever you can - be it in a pure equity fund or a multi-cap fund. Just be very aggressive about it and make sure that you are not touching that money. A period of 10-15 years is good enough to support the income for another 10-15 years.
Having said that, even if you have not been able to save and invest, you may have been able to build some other assets. Assets are fungible. For example, if you have three houses and no investment, some houses can be sold to actually support your investments unless all your savings and investment have been consumed. This is not an unusual situation in a growing family where a kid's education needs to be taken care of or in the initial phase of someone's career when households have to be run. In such cases, people are unable to save for a very long period of time.
However, now when you actually want to get going with your investments, make sure that by tomorrow morning, you have your investment account open and you start with your SIP. Try and save as much as possible and invest for at least 10 years.