Organic-inorganic　metal　halides　(OIMHs)　have　become　a　research　hotspot　in　recent　years　due　to　their　excellent　luminescent　properties　and　tunable　emission　wavelengths.　However,　the　development　of　efficient　red-light-emitting　OIMHs　remains　a　significant　challenge.　This　work　reports　three　Mn-based　OIMHs　derived　from　1-methyl-1,2,3,4-tetrahydroisoquinoline　hydrobromide:　racemic　one　(Rac-TBM)　and　chiral　ones　(R-TBM　and　S-TBM).　As　a　result　of　the　synergism　of　chiral　organic　ligands　inducing　a　unique　lantern-shaped　hybrid　structure　containing　both　tetrahedra　and　octahedra,　Rac-TBM　exhibits　red-light　emission　with　near-unity　luminescence　quantum　yield.　In　comparison,　the　chiral　counterparts　R/S-TBM　display　strong　green　emission　and　circularly　polarized　luminescence　(CPL)　with　a　glum　value　up　to　±2.5×10−2.　Interestingly,　a　mixture　of　R-　and　S-TBM　can　transform　into　Rac-TBM,　successfully　achieving　a　sensitive　and　reversible　switch　between　red　light　of　octahedra　and　green　light　of　tetrahedra　under　external　stimuli.　The　outstanding　luminescent　properties　allow　Rac-TBM　to　be　utilized　not　only　for　X-ray　radioluminescence　with　a　detection　limit　down　to　46.29　nGys−1,　but　also　for　advanced　information　encryption　systems　to　achieve　leak-proof　decryption.　©　2024　Wiley-VCH　GmbH.