Why CTC and take-home are so far apart
Cost to company is what your employer spends. Take-home is what survives after four separate deductions, and in India they compound in an order that is easy to get wrong. Your employer's EPF contribution is inside CTC but never reaches you. Gratuity accrues but is not paid monthly. Professional tax is levied by your state, not the centre. And income tax is computed on a taxable figure that is neither your CTC nor your gross.
The gap between the two numbers is routinely 20–30% of CTC, which is why an offer that looks like a raise sometimes is not one. This calculator shows every deduction as its own line so you can see which component is doing the damage.