I did the numbers for this for a friend a while ago, here was what we concluded with (financial statement styled), for Careem only:
You can earn around 100,000-110,000 by meeting the minimum targets on Careem, average 105,000rs for 10 rides daily, 30 days a month. That's your revenue.
Revenue: 105,000
Tax: 3050
Tax is deductible here because this is your income, all further expenses etc. come at your own behest. I'm not sure if Careem cuts taxes on the payments made, this is worth looking into.
Gross income: 101,950
Costs
- Driver: 25,000
- Fuel: 33,000 (6000km monthly, 500ltr at 12km/ltr average)
- Maintenance: 4,000 (oil, tuning, filters etc.)
- Depreciation of asset: 6,500 (based on the price difference of getting a new City ~16lac vs a 5-year old city ~12lac over 60 months)
- Insurance: 5,000
Net Profit: 28,450
Which is to say, you'll be earning 27-30k per month that you can spend anywhere. The depreciation money is assumed to be reinvested after 5 years in selling the old car and getting a new one.
If you have the spare money to buy and manage some cars, 2-3 cars can net you almost 100k extra per month. This doesn't include the headache of maintaining the cars and managing your drivers.
If you however have a full time job and want to consider driving Careem instead, I don't think these numbers will please you, the same way my friend decided it wasn't really worth it. 
