They are seeking a cancellation of the 70th Integrated Combined Competitive (Preliminary) Examination (CCE), 2024.
The demonstrating aspirants, who were firm on meeting state CM Nitish Kumar, reportedly tried to break the police barricade when cops lathi-charged them.
Security was beefed up close to Hotel Maurya in the city to contain the protesters.
The protests have been happening in the Bihar capital since the prelim exam was conducted on December 13.
Jan Suraaj Party Prashant Kishor had extended his support to the aspirants.
"I must say that irregularities and paper leaks have now become the norm as far as BPSC exams are concerned. It can't go on like this... We have to find a solution," he was quoted as saying to the protesters as reported by India Today.