Has your brother ever applied for any other visa from Canada before? If so he should have a UCI number that he can use to log into ECAS and check the status of his application.
If not, did your brother pay his fee using a credit card or demand draft?
If credit card, has any charge appeared on his credit card?
If demand draft, can you check with whoever issued the demand draft to see if it has been presented for payment?
Did your brother supply an e-mail address with his application? If so, and if the application was in the cap, was reviewed and found to be complete and eligible, CIC should have e-mailed him by now to inform him. But sometimes the e-mail is delivered to the spam folder or something like that.
Because it's been over 3 months you can call CIC to find the status of your application. I don't have the number handy, but if you ask in the main 2013 or 2014 applicants forum you can get it.