Why CTC and take-home look so different
CTC is a company's accounting figure for what you cost them annually — it's not what you receive. Two of the biggest gaps between CTC and take-home are things you never see in your bank account at all: the employer's PF contribution and, for many companies, other benefits like insurance premiums or gratuity provisions. On top of that, your own PF contribution and income tax come out before the remainder hits your account — which is why a ₹12 lakh CTC often works out to noticeably less than ₹1 lakh a month in hand, even though the arithmetic "should" be close.
The basic salary percentage matters more than people realize, because PF is calculated as a percentage of basic, not of CTC. A company that structures your CTC with a higher basic salary percentage will deduct more toward PF (lowering your immediate take-home but boosting your retirement savings) than one with a lower basic and more allowances. Neither structure is "better" outright — it's a trade-off between more cash now and more forced savings — but it's worth understanding when comparing two job offers with the same headline CTC.