What all subjects are there in BBA and MBA? Are there specialisation courses available in BBA like BBA in HR or BBA in marketing?

You may refer to following link to have an idea about BBA syllabus: http://ipu.ac.in/syllabus/affiliated/bbabi.pdf. Different universities may have minor difference in syllabus. Some Universities offer functional( Marketing , HR etc) or sector specializations ( IT, Retail, Travel etc) in BBA.