What is meant by 'increase' in supply? 

An increase in supply is a shift of the supply curve to the right (e.g. from the initial supply curve to the new supply curve). It means that sellers are willing to supply a greater quantity of goods at the same price level. Otherwise an increase in supply due to favourable factors (like increase in technology, climate etc) other than price of the good. For example, sellers were willing to supply 2 units of goods at a price of Rs150 before the shift, but are willing to supply 6 units of goods at Rs 150 after the shift.