Hello aspirant,

Based on gate eligibility,there is no such restrictions insisted on previous year exam score.For Gate 2019 eligibility criteria  go to

https://www.google.com/amp/s/engineering.careers360.com/articles/gate-eligibility-criteria/amp

There it doesn't say anything about previous attempt. 

Hi student,

Its okay if you have negative score.

Following is the eligibility criteria for B.Tech or B.E. graduates gate examination:

• There is no any age limit or a number of attempts limit for the GATE.
• Passed a Bachelor degree (4 years after 10+2 or 3-years after Diploma in Engineering/Technology) in Engineering/ Technology or currently in the final year of the degree.
• Year of qualification must not be later than 2020.

As long as there is no official notification, the above will be the only eligibility criteria for gate 2020.