Usually to get admission in agriculture business management(ABM) you have to give entrance exams like CAT,MAT,XAT,CMAT etc.In case of direct admissions you can try directly contacting the college you are interested in and try asking if seats are available via direct admission.You can visit the below link https://bschool.careers360.com/colleges/list-of-agriculture-business-management-colleges-in-india

and download the brochures of the colleges you are interested in to know about their placement and admission processes.