Hello ,
you can include a TRI colour dress code for all staff on republic day. Also the entire office can be decorated with TRI colour ballons and flags along with a small flag on each workstation. This will give a feel of patriotism all around.
And organise a quiz competition among your staff. Frame the questions in such a way that answer should containing the information of our constitution, because it will give us much knowledge about our constitution.
!!!! WISH YOU HAPPY REPUBLIC DAY !!!