Yes there will be some effect but the value of GATE will not deteriorate. GATE is an exam whose primary motive is to get admissions in MTech and PhD in various institutes. Although, it is used by PSUs to recruit candidates. But there is a procedure for recruitment in each PSU. They shortlist the GATE qualified candidates and then call the top rankers for interview. It can be a series of interview from PI to TI or only a single interview. After lifting ban only the perimeter of candidates will increase, but the non- IITians will still have their chance and place in PSUs. Again, it depends on PSU that how much candidates are they taking from GATE and from placement. There will be no difference for the GATE rankers till AIR 100. But after that there can be variations. So my best advice is to give GATE exam very sincerely and get good rank. Fill the form of respective PSUs of your branch and let the recruitment process begins. After a year or two year's analytics we can predict the real effect. Best of Luck..