Olive Tree's can live indoors for a time, and with some minding. Find a nice sunny spot, ideally where your tree can occasionally breathe in some fresh air. Plant in well-draining soil with a few inches of gravel at the bottom and plenty of drainage holes to ensure water does not pool at the roots.
Comfortable in the dry environment of the Mediterranean, your Olive Tree prefers dry soil between waterings. Allow your tree to vacation in the outdoors for a few days 3 or 4 times per year and you will be rewarded with a more robust plant, and maybe even some fruit.