What is the proper proportion for train and test set for classification system?
In short theres no best proportion or rule of thumb.
It's highly dependent on how much data you have, its distribution in relation to the number of labels, and if samples are related to each other in anyway or are they completely independent of each other.  You could look into k-fold training. Say you split your data into 5 sections each 20 percent of the size of the entire dataset. For each split of 20 percent of data use the remaining 80 percent of data as the training set. Go through each 20 percent of data and use that as the test and the rest as the training. Make sure your labels are evenly distributed between splits.
K-fold reference