The only branch for which that’s true is probably CS and its derivative branches, getting 10+LPA CTC is Computer Science is ridiculously common. Even complete idiots that can barely code have 8.5 LPA jobs thrust into their faces.
Real picture- average salary 6.5-7.5 LPA on campus, depending on which IIT you go to.
In non-CS your only chance of getting a 10L+ CTC in a core company while being <7 pointer is by joining a PSU- and there the cash component is just 4/5 lakhs- less than people who get 6 lpa at an MNC
Lots of people get shitty jobs even from IIT. It goes as low as 3.75 lakhs. Luckily, doing that badly is just as hard as doing well enough to get Schlum or ITC, and since the average salaries are higher there is a higher chance of getting a 10+LPA offer than all other Indian schools.
Also people seek out off-campus job offers as well, along with on-campus ones, so the average rises a little (maybe 0.2-0.5LPA) by the time they join the work force, but that’s not because of placements.