Upgrading my mentorship to 6+6 months.

Hi,I just have some doubts .I have taken a mentorship program for 3 months. Now Can i upgrade it to 6 + 6 months by paying the amount needed for the purchase.
I have take mentorship with nearly 17k for 3 months. The 6 months mentorship is nearly 22k,now can upgrade my 3 months to 6+6 months by paying remianing amount of 5k.Or is their any other process for it?

Thank you