i'm using GridSearchCV to find parameter C for SVC() classifier present in sklearn.svm . I'm not getting the optimal result desired
You didn't do any cross validation of data in GridSearchCV as you didn't mention any cv parameter. So what GridSearchCV did is it found the best estimator on the train set which possibly made the model overfitted on training data. You should use cross validation to find the best best estimator.
abc = GridSearchCV(clf,params,cv=5)