How should one ideally spend the 40k per month salary in Pune or Banglore in India, and how much should one save and invest?

Use this formula and you will be happy

When you start out, do not worry about this at all. I know how I worried about these things, rather than focusing on job. Your initial days/years are very very important where you develop a really strong foundation. Having said that, first of all categorise how much you will pay for rent. This is the biggest of all expenses. Once you decide on this and get a good place for yourself, you can plan the rest of budget later once you start living. Give it a couple of months to see how your life is and most important thing is monitor everything you spend. The intention is to observe and then tweak your lifestyle to maximise your spending/saving priorities. Do not get stressed :) observe, apply, tune and repeat!

As a bachelor you should stay in a Paying Guest accommodation or hire an apartment jointly with friends, and manage your monthly expenses within 25000.Let me show you the advantage of an early start in savings. Suppose you start saving today and your friend who likes to live in “a very good style” enjoys life and starts saving 5 years later. Let us compare the two corpuses By saving Rs 20000 per month and increasing your savings by 10% every year and investing in a Mutual Fund that gives you a 15% annual return Your corpus after 5 years will be Rs 14.43 lac (http://jagoinvestor.com/calculators/html/Increasing-SIP-Calculator.html Your friend in style will have nil bank balance after 5 years. 35 years from now your this corpus of 14.43 lac @15 will grow to Rs 9.5 crore against nil of your friend See how costly it will be living in style.You may like to spend 5000 more on your style and make up for it in later yearsAll the best to you