Below are some of the Sanskrit greetings that can be used to convey your well wishes on the occasion of Dasara in Sanskrit:
Happy Dasara
शुभमयी दशहरा
Happy Vijaydashami
आनन्दमयी विजयदशमी
In the above two cases of Sanskrit Dasara greetings, you can use the words मङ्गलमयी or शुभकरी or कल्याणमयी can also be used at the place of शुभमयी or आनन्दमयी।
Wishing you a very very happy Dussehra
दशहराशुभकामनाः
Sending lots of love on Dussehra
दशहरापर्वणि वितनोमि सुहृद्भावम्
May this Dussehra bring job and prosperity
दिशतु दशहरा प्रसन्नतां समृद्धिञ्च
