As other members have explained, DA is paid to compensate for the rise in inflation. It is not mandatory for private sector employers to show it separately. However, there is a recognized practice to structure the pay into Basic Pay, DA/VDA/IDA, HRA, TA, etc., so that various related liabilities are calculated easily with less financial burden on the employer. The government notifies an increase in minimum wages based on the price index, which is applicable to private sector employees. However, its implementation may be a question of fact.
Regards,
Srivastava