i scored 6700 rank in GATE2019,CIVIL paper.With gate score-522.Will i get top NIT's? Is there any chance of getting in any IIT?OBC category

As per your score and previous year cutoff, the colleges you get in first round are:-

IIT Delhi Civil Engineering Construction Engineering and Managment

IIT Delhi Civil Engineering Environmental Engineering and Managment

IIT Delhi Civil Engineering Rock Engineering and Underground Structure

IIT Delhi Civil Engineering Geotechnical and Geoenvironmental Engineering

National Institute of Technology Srinagar Department of Civil Engineering Water Resources Engineering

National Institute of Technology Agartala Department of Civil Engineering Environmental Engineering

National Institute of Technology Patna Department of Civil Engineering River Engineering

National Institute of Technology Manipur Department of Civil Engineering Environmental and Water Resources Engineering

National Institute of Technology Agartala Department of Civil Engineering Seismic Science and Engineering

To know more about your chances of getting other colleges check out the PSU/college predictor link below:

https://engineering.careers360.com/gate-college-predictor