Which course should I prefer after completing BCA?

You can pursue MCA after BCA. MCA is a good course and will fetch you good job opportunities.

After BCA, you have two option. You can pursue MCA (Master of computer application) or MBA. If you want to continue your career in computers, you can pursue MCA. If you want a career in business or management, you can go for MBA. I think, MCA is best for you. Don't change your field.