The available payment plans depend on a couple of factors: 
1. PayLater partner 
2. Order amount 
3. Customer credit limit 
4. Customer risk profile, etc. 

Below are the most common PayLater options: 
1. 30 days or One-Time Payment 
2. 2 Months 
3. 3 Months 
4. 6 Months 
5. 12 Months

Please be informed that Xendit/merchant are not the ones to decide the tenor or installment plans, but our partner will be the one who decided due to the factors above.

Can read more of this via this reference, here.