Software Engg & Web Technologies is not in the syllabus, check 2022 syllabus. https://gate.iitkgp.ac.in/gate_syllabus.html (It was removed after 2016 I guess).
Don’t go by weightage of subject which you have calculated. There is nothing mentioned in official syllabus other than the distribution for Apti, Eng Maths and Branch Paper, and it can vary from year to year. Try sticking to your time table according to your weak and strong areas and solve PYQs and standard questions to keep a check on your understanding of concepts. All the best !