Normally we advice to do brushing covering all the surfaces in 2-3 minutes. If you are not able to do in 2-3 minutes nothing wrong in 5-6 minutes. Only thing is dont over brush which might lead to abrasion of enamel. Speed of brushing varies from person to person.
Next Steps
Please learn the correct way of brushing from your dentist
Health Tips
Use soft toothbrush. Brush 45degree angulation from gums to teeth.