For an office, it is best to keep a small, clean, and simple Jain idol or image that supports peace, discipline, and remembrance of Dharma.

Good choices are:

• Lord Mahavir Bhagwan — for ahimsa, self-control, and inner calm
• Tirthankar idol in meditation posture — for peace and concentration
• Namokar Mantra frame or symbol — if you prefer something simpler and highly respectful

Important Jain guidance for office placement

• Keep it in a clean and respectful place
• Place it above eye level if possible
• Do not keep it near unclean items, papers on the floor, dustbin, or shoes
• Avoid using it as a decorative item only; keep the भावना of reverence
• If the office environment is very busy, a small marble or metal idol is suitable

Best simple recommendation

If you want one idol, keep Lord Mahavir Bhagwan in a seated meditative posture. This is especially suitable for an office because it represents peace, equanimity, and right conduct.

If you want, I can also tell you the best direction to place it according to Jain tradition.