During gate preparation you need people around you who can keep you in right track. Sir and Mam for me was one of those. Sir’s DBMS, TOC, Discrete Maths lectures are of high quality (you can see sample ones in Youtube). Great thing is,Sir right now provides online lectures too .So anyone can take his full course now. Even though I prepared textbooks, I always asked them for help in case of any doubt. Sir and Mam always helped me despite of their busy schedule. In fact I have seen them offering their course for free to some students who are going through tough periods. Finally I would suggest everyone to take test series provided by GATEBOOK. Honestly speaking, if someone take the GATEBOOK test series ,there is no need for any paid test series. It consist standard questions which are on par with gate level.