While "flats" can mean different things in different parts of the country-- I assume it to be urban metropolitan living.

You are looking for single or upscale contemporary and stylish couple. Here, they are looking for night life, convenience and mass transportation. Many live where they work. Depending on the area, they may not own a car and are looking for an area that will support that lifestyle. They are environmentally aware and conscious.

I'd start with realtors that support that type of client. These aren't those catering to families. If there are employers nearby I'd target them. I'd put myself in the types of things they read. Place yourself near where they shop, and the types of shop they'll be patronizing. Advertise with the arts, host a design competition, get press regarding your enviro attributes.

Just a start...

This is going to need a little imagination.

Okay, you are in a business that needs a lot of imagination.

My idea is to find those magazines that your customers like. You live in the area and should have a pretty good idea. You can target these through the Google Display network (you can access it as part of Adwords).

Make up some interesting little advertisements

"Oh! There is this wonderful flat in Andheri that is just lovely. 85 lakhs!"

"Don't like renting? Lots of lovely flats in Andheri. 50-150 lakhs"

you will need a landing page ... the sneaky bit is that if you don't have a website yet, you can use someone else's*. They get the traffic. That at this stage is irrelevant. You want to know how many people are interested.

The number of people clicking will tell you that. From there you can build up your campaign, or run it down if it doesn't work.

*Do make sure they aren't advertising on the display network, or you will skew their results ... ;-)

There are other ways, this is one of the better ones.

To your success Moriarty xx