Hi,
You must understand the basic concept of dearness allowance. It is a payment towards the rise in cost of living, which is calulated based on cost of living index.
As regards the minimum wages, the State government or the central Government makes a notification and payment is to be made.. With regard to payment at a higher level, the coimpany can formulate its own scheme for payment of dearness allowancxe. It can be a fixed percentage of the basic pay, or on a sliding percentage, as per company's schem and policy.
Please remember, once the company is paying more than the minimum wages, it can formulate its own scheme for payment of dearness allowance. Needless to say that all other factors like, region cum industry, capacity to pay etc are taken in to consideration by the company .
Cyril