Dear,

In general BITS-HD has more emphasis on theoretical questions as opposed to the numerical type questions in GATE. The number of questions to be attempted in 120 mins is around 100 which is similar to the pattern of IES. So, my advice to you would be to go through the previous year IES questions thoroughly along with GATE papers, and focus more on theoretical aspects of the important topic of mechanical. Also, there are few extra topics in BITS-HD syllabus as opposed to that of GATE, do make sure to prepare them as well. Prepare well for first paper as well( Maths and English you can score fully with sufficient prep), because more often than not, people scoring well in first paper get an extra edge over others. For getting Pilani Campus try getting close to 190 out of total marks, which should get you any branch of your choice. All the very best. Do visit the following site for the syllabus.

https://engineering.careers360.com/articles/bits-hd-syllabus

Hope this helps!