If you go to the Help Center on FamilySearch and put "types of IGI" in the search box, you will find information and directions. There is the contributed IGI which is found under "genealogies" on the search function and the other is the International Genealogical Index which can be used by doing a regular search as those records are included in the FamilySearch records.
Here is the direct 'link' (ie. URL) to search the current ('On-Line') "Collection" for the "International Genealogical Index" (IGI):
I hope this helps.
ps: Copies of the original "Sheets" MAY be available at the "Family History Library" (FHL) of the Church in 'Temple Square' in Salt Lake City, Utah, USA; but, to how accessible, that is another question ...
pps: And there may be, "Microfiche" (but, not the original "Sheets"), of the "International Genealogical Index" (IGI), at the FHL; and, also, at some "Family History Centres" of the Church, around the World (and, possibly, some "Affiliate" Libraries, around the World).
any info that was originally in the IGI should now (normally) be listed in the FamilySearch Family Tree?
do a find: https://www.familysearch.org/tree/find/name