1. Dont worry, as you are in no way responsible for the SC decision. Any candidate can compete as a general candidate and in your case, at the time of online submission, you had mentioned that you belong to OBC and may not be your particular caste, since you were under OBC category at that point of time.
2. By producing the OBC certificate that you belong to Jat community, it will in no way affect your candidature as a general candidate and will not affect your written exam result, since the result was published after the SC judgement and the authorities would have taken note of the SC judgement.
3. There is no by chance and the bank if it selects you will select you under general category only in view of SC judgement and your apprehension that in future if your documents are rechecked and finds that you had applied under OBC category but still the bank would not have considered you as an OBC candidate but as a general candidate and there will be no danger for your job in future. Intentionally you have not concealed any information and because Jat community was under OBC reservation category at the time of your applying, you had applied under OBC category. However in view of SC judgement, all those candidates, who belong to Jat community, who had applied under obc category will be treated as general candidates only.