Gate is a National level Exam and the rank in gate is based on the marks you scored in the exam.

The rank is not fixed every time, the companies did not recruit people based on the same gate rank every year.In order to get  a good job or a good college for higher studies you need to have your rank below 1000.

You should exhibit 100 percentile to get a   good job for open category.

Also, the reserved category candidates do not need to have such high percentile to get a job.

In 2017 ,Gate Qualifying Marks are:

Branch                                General category                    OBC

CE                                          28.70                                       25.8

CS                                          25                                           22.50

ME                                          32.87                                       29

your rank must be under 300 if you are from general category

<450 for OBC category

<800 SC&ST category

but the rank doesnt ensure your selection you will have to go through the interview process well if the rank is below 100 it makes the interview process very lucid

all you have to keep in your mind during preparation is that your marks must be above 65 to have a strong chance.