Known as the Silicon Valley of India, Bengaluru is a land of start-ups and nifty ideas. This metro economy can seem a little tight, especially if you run low on cash. But there&rsquos a lot to do here for budget travellers. From art to book readings and more - the city is full of wonders that come at no cost. Namma Bengaluru has something for all &ndash here&rsquos your guide to meandering through some of its zero-pay destinations.