Whenever you buy a car or a house, it is always the right time for it! 
Now, considering the current situation, I would advise to not wait for coming models, and go for the current models; Suzuki Cultus / Celerio, Honda City, Suzuki Ciaz, or any Corolla variant, matching your budget and requirements.
Locally assembled Hatchbacks / Sedans from new entrants will be available in 2020 at least IMO. At that time, if you would be interested in some; you can always sell your current vehicle and buy the new one. Your current vehicle will sell at a good, reasonable price, since prices of new cars / upcoming models will be always high. You may not suffer any loss in selling of your car (other than normal depreciation, etc.)
