I am from Bangalore. I freelance as a python developer.

Tough this is not passive income this might give an idea: Billing $20/hr (that's what we get in Bangalore), getting $500 a month from a single client is very easy. But finding few more clients will get you more than what you want. You will also get a lot of time. Toughest part is getting the client, good clients usually come from your contacts.

Another thought, finding customers for your SaSS product will not be difficult if you have a good circle, attend conferences and workshops in Bangalore which will build you this circle.

I do a day job as openstack dev, freelance on django, and also working on my own ideas - I am doing this to pursue my passion of traveling(digital nomad). :)