presently there are still 11 berths available in 18463 between EE and SBC for journey on 5.9.2016. Also, you are not eligible for any quota other than General Quota.
For better chances of getting a confirmed lower berth, you may either visit your nearest PRS Counter and request the booking clerk for the same, else you may try your luck again through IRCTC. But please note that there is no fool-proof way of getting a confirmed Lower Berth through IRCTC, other than selecting the option 'Book my ticket if at least one lower berth is allotted' and still there is a risk of getting allotted a side lower berth again. Also keep in mind that the charges for cancellation of confirmed...
more... ticket is very high (in all the classes)