If you are dead interested in Mathematics and Computing and are targeting Placements, MnC at IIT ISM Dhanbad is good and has good Placements. However if you are planning a career in research or pursuing Masters or Doctoral degree from US, I believe you should select IITR above IIT ISM.

IIT ISM is an excellent technical school when it comes to Core Engineering Branches, but as far as MnC is concerned it doesnt have that Good Faculty and Research Facilities. Not many of the Top MnCs barring the usual Amazon, Microsoft and Goldman Sachs visit IIT ISM Dhanbad, unlike Other Top 8 IITs. However the median package at IIT ISM MnC is somewhere around 15 LPA and provides nearly 90% Placement each year.

However, IITR is knots ahead of IIT ISM when it comes to faculty, infrastructure, campus culture, technology and research. Even if you are interested in IT/Software/Finance IITR provides infinite opportunities to nurture and cultivate your interest. It is one of the IITs where is a option of changing Branch twice, after the first and second semesters on basis of merit so you may also consider that.

As far as Mechanical at IITR is concerned it is one of the Best in Campus with excellent curriculum. Core companies like Tata Steel, Maruti Suzuki, ITC , Airbus, Reliance as well as Non Core and IT Organizations like Morgan Stanley, JP Morgan, American Express, EXL, etc. are regular recruiters in campus. All the Best.

For more information and college prediction do refer the link below

https://engineering.careers360.com/articles/jee-adva nced-preparation-tips