Megha,
You started the thread in a wrong manner.....
First, understand, legally there is no rule that says how salary will be structured. It is the. Notice of the company to decide what it will do and how it will break up the of the salary. There are certain norms you will find on this site and on other forums, sites and books. However, you are free to decide your own structure.
However, there are some rules that you should follow to avoid problems, some of which members tried to explain to you above.
1. Ensure that Basic + DA is more than minimum wages. That is a requirement of law. Check with the latest state notification for minimum wages.
2. Check if hra is compulsory (as far as I know, Maharashtra and Gujarat are the only states that provide for compulsory hra amounting to 5% of basic +da). Income tax allows tax free hra up to 40% of salary if the employee actually pays house rent. So it would make sense to provide an amount of hra that gives maximum tax benefit. Speak to your accounts head, he will help you work that out.
3. An amount if Rs. 800 per month is allowed to each employee as tax free travel allowance. So you can provide for that in the structure
4. Companies generally try to reduce basic and da since a lot of statutory benefits are often computed on that basic. However, I believe that is a fallacy that has resulted in companies creating a number of allowances unnecessarily. I believe that you should create allowances that actually make sense (eg additional allowance for night shift)
As desired by your management, you can adjust your structure without disturbing the total take home or CTC.