BITS Pilani should open up in September. The country will probably not recover from the pandemic before this. With the number of vaccinations going around, it will take some time.
You can think about a little, there are about 10 lakhs JEE Main applicants. Of this, only 5000 are selected for IIT. Even if we consider the death rate of just 18 to 20 years old, it is about 0.05%. This is equivalent to the number of people selected by IIT.
Even if lives are lost that are equivalent to the IIT intake, nothing much could happen. In the end, the decision is to be taken by the Senate and the guidelines provided by UGC. If nothing materializes, the online classes will definitely continue and any changes will be informed by the authorities to students.