Hello Harshita,
I checked if it is possible to change Fiori Launchpad Header for UIS. Unfortunately there is no "easy" way to do that.
But with some "hacking" it is possible as the implementation for the SAP HANA Cockpit shows. Pre-Condition is that you are using at least one self implemented tile which allows you to inject the coding to set the header. Following I give you briefly the hints in which files you can find the implementation for the setting of the header in the SAP HANA Cockpit (which is also a Fiori Launchpad implemented mit UIS). It would be to much to duplicate all the steps here:
1) sap.hana.admin.cockpit.tiles.ActiveSessionsTile.controller.js: In the onInit function of that tile controller implementation. function addTile of sap.hana.admin.cockpit.utils.TilesHandler.js is called. That onInit method is executed if the tile is displayed on the Launpad. As you can see for the other tile controllers the same method is called in the onInit function of every controller. So if at least one tile is displayed the header is set.
2) sap.hana.admin.cockpit.utils.TilesHandler.js: In the called function addTile, function initCockpit of sap.hana.admin.cockpit.utils.Cockpit.js is called.
3) sap.hana.admin.cockpit.utils.Cockpit.js: In the called function initCockpit, function injectHeader is called. In this function then sap.hana.admin.cockpit.utils.ShellHeader is used to trigger the change of the header.
4) sap.hana.admin.cockpit.utils.ShellHeader.js: Here finally in the constructor the logic can be seen which is used to set the header. But to inject the header an own ContentRenderer implementation is used (sap.hana.admin.cockpit.utilsContentRenderer.js).
That is really just a brief highlighting of the code positions relevant for the SAP HANA cockpit which lead to the Fiori Launchpad header setting. You can extract and simplify the relevant coding for your case if you wanna make that effort 
.
Regards,
Florian