Atanu, To be honest, it is very difficult to predict the cutoffs and the predicted rank of IIT JAM Mathematics, but we can make use of previous year trends to calculate the expected rank and cutoff. Firstly discussing with respect to the cutoff, it is a big possibility that you would clear the cutoff irrespective of your category as many coaching institutions predict it to be around 20. However, predicting the rank is a bit more difficult as it also depends on factors like total number of candidates and difficulty level of exam which varies every year and we cannot predict the toughness of the paper and its effect on the rank as of now. However, looking at past few years trends , you can expect a rank close to 220-245, maybe even less depending on the variables as discussed above. However, it is still advised that do not rely totally on these predictions as they are largely dependent on previous years trends, however, it also helps us in understanding our chances.

Hope this helps.