hi,

see since you have taken the six subject you have to clear the all six subject with the pass score to obtain a better career, you did not mention from which of the board you would be appear in 12th exam, however in west bengal board of higher secondary education, best of five is taken to make the 12th result, so if one of the subjects is failed , students get the promotion. now if you want to go for engineering you must note that during the job interview your overall score and the pass marks of each subject would scrutinize and if you have failed in one subject you may not eligible for many of the mncs. so study hard and get the pass marks in all subjects including the practicals.