**Income components:**

Mr. Z, who stays in Mumbai in a rented accommodation, has received the following emoluments from his employer during the financial year 2016-17:

1. Basic Salary: Rs. 72,000
2. House Rent Allowance (HRA): Rs. 10,000
3. Bonus: Rs. 5,000
4. Commission on Turnover: Rs. 3,00,000 (including Rs. 50,000)

**Calculation of taxable income:**

To calculate the taxable income, we need to consider the various income components and their tax treatment.

1. Basic Salary: The basic salary is fully taxable under the head "Income from Salaries".

2. House Rent Allowance (HRA): The HRA is partially taxable. The least of the following three amounts is exempt from tax:
a. Actual HRA received: Rs. 10,000
b. Rent paid in excess of 10% of salary: Since the monthly rent is Rs. 600, the annual rent would be Rs. 7,200. As 10% of the salary is Rs. 7,200, no amount is paid in excess of 10% of the salary.
c. 50% of the basic salary for individuals living in metro cities: 50% of Rs. 72,000 is Rs. 36,000. Therefore, the exempted HRA is Rs. 10,000.

3. Bonus: The bonus is fully taxable under the head "Income from Salaries".

4. Commission on Turnover: The commission on turnover is taxable under the head "Income from Business or Profession". It will be added to the total turnover earned by Mr. Z and taxed accordingly.

**Tax calculation and deductions:**

After determining the taxable income, the applicable tax rates will be applied based on the income slab to calculate the total tax liability. Various deductions and exemptions can be claimed to reduce the tax liability further.

Some common deductions available to individuals are:
- Standard deduction of Rs. 40,000 (for FY 2018-19).
- Deduction under Section 80C for investments in specified instruments like insurance, provident fund, etc. up to Rs. 1.5 lakh.
- Deduction under Section 80D for medical insurance premium paid.
- Deduction under Section 80G for donations made to specified charitable institutions.

These deductions should be considered while finalizing the tax liability.

**Conclusion:**

In conclusion, Mr. Z's taxable income will include his basic salary, bonus, and commission on turnover. The HRA received will be partially exempt from tax based on the calculations mentioned above. After calculating the taxable income, the applicable tax rates and deductions can be applied to arrive at the final tax liability. It is important for Mr. Z to consult a tax professional or use online tax calculators to accurately determine his tax liability and ensure compliance with the income tax laws of India.