Hi Shabina,
Let me give you an idea of the break-up for any CTC assigned to an employee.
Usually, we take:
Basic salary: 50% of CTC (No thumb rule)
HRA: 50% of Basic salary for "A" class cities and 40% for "B" class cities P.S. cities under the minimum wages act.
Conveyance: If a person's gross amount already shows that it's "taxable," you can't manipulate it abruptly to make it non-taxable. i.e. try to fix conveyance in the ratio of the tax slab (for the non-taxable amount, keep it <= 800 per month, 9600 is the tax-free amount).
The rest of the amount should be adjusted accordingly in heads of Medical allowances, Education Allowances, Special Allowances, etc.
You can reduce the net salary amount by bifurcating the part into Gratuity, Bonus, and Earned leaves per month, but more or less, it's a kind of malpractice, and I won't advocate it.
Note: try to keep the amount of Basic salary in such a way that it won't cost too much in terms of contributions under various Labour acts. i.e. EPF, Bonus, Gratuity, etc.
I hope this could give you a better idea of what sorts of points should be taken into keen consideration while preparing a salary break-up.
Regards,
Manish Gupta