Dear Hina.1661,
Before you make up the policy and circulate it with the employees, kindly note that as you are making a policy which states that late coming will not be tolerated and deductions will be made. In short, you are asking for employees to respect the incoming time. At the same time, if your management has a style where the company's work starts only in the evening, then most people will extend their outgoing time. So, the moment you press for standardization on the in-time, employees will standardize the out-time. If this does not suit your industry, a flexi-time module needs to be implemented.
Think, speak with management, analyze the outcomes, and then plan your adaptive policy.
Regards, Ashutosh Thakre