Hi Sandeep Kaur,
The Republic Day celebration cannot be complete without flag hoisting and singing of the national anthem. All other activities can follow, such as a general salute by the parade commander/security staff, a speech by the Head of Office/chief guest, distribution of sweets, dances or skits by family members of staff, and distribution of mementos to kids for fun games, etc. Depending on the size of your office/staff and circumstances, you can organize the event accordingly.