The rate with which the rental market grows is known as the rent inflation rate, which gets calculated by taking the percentage of increase compared to the base rent of the previous year. Mumbai, the city posing the costliest real estate in the country, affects the rental dwellers adversely too. When compared to other Indian mega-towns like Bengaluru, Delhi NCR, Chennai amongst others, Mumbai shows the highest increase of about 18%.

Further study shows that despite an expensive existing rental market, Mumbai's willingness for a bigger house is increasing too. There is an increase in demand for 2 & 3 BHKs as compared to 1BHK in the previous years. Mumbai's evolving demography is thought to be the prime cause for this occurrence as more and more budding families are wanting a comfortable life closer to their preferred places of work or study.

Source