Yes even the GK section of MAT has negative marking... It is +1 and -0.25 scoreline.

Although,  the marks of the GK section   are not considered while calculating the MAT percentile, however, a number of MAT institutions consider candidate's GK score in the second round, so that is the role of GK , it would be great if you score good marks  in GK as well but you should focus on GK only if you are done with the preparation of other sections of Mat paper as according to past MAT exam toppers like Ketan Anand, it is not necessary to attempt GK questions. The section is not taken into account to calculate your percentile and merit score. So you should  save your time on the last day to MAT  exam and ensure that your first 4 sections are well prepared and attempted.