can you keep small box braids in for 5 months
I think that's kinda long. 2-3 months is longest I've heard is good for you.
2 months is ideal. But 3 months is the absolute max
Leaving braids in for 5 months will result in a matted, tangled mess for the vast majority of us. I wouldn't leave a protective style in for longer than six weeks, because any longer could impact your hair's health or lead to scalp infection. If you must stretch beyond that point, remember to cleanse your scalp regularly.