I feel that we need some more information to help for your situation. Still though I think the best start in any fundraising difficult situation is to find out who exactly is telling you no. If you know who is telling your team that the team cannot fundraise then it is much more simple to get the problem resolved. The first step is to go to that person directly and ask him/her why your team is not given the opportunity to fundraise. The next step is too explain to that person the costs of running an frc team and then explain the need for proper fundraising with a cost/profit graph showing the expected money that your team would gain from doing the fundraiser. If your team is still stonewalled after showing that doing fundraiser "x" will help fund the team by "y%" then your team's next option is to get either(preferably both) administration/school board support by reaching out to these people. If the entire school district is against you(highly unlikely) then the best solution is to form an independent nonprofit club from your team members parents. Many athletic booster and band/choir booster clubs are formed this way that still work well in a district.
I hope I helped but internet forums can only provide so much. To succeed in fundraising it takes a team effort and I wish your team good luck.
John