Everest (definition 1975) - EPSG:4045

WKT

GEOGCS["GCS_Everest_def_1975", 
	DATUM["D_Everest_Def_1975", 
		SPHEROID["Everest_Definition_1975", 6377299.151, 300.8017255]], 
	PRIMEM["Greenwich", 0.0], 
	UNIT["Degree", 0.0174532925199433]]

WKT2

GEOGCRS["GCS_Everest_def_1975", 
	DATUM["D_Everest_Def_1975", 
		ELLIPSOID["Everest_Definition_1975", 6377299.151, 300.8017255]], 
	PRIMEM["Greenwich", 0.0], 
	CS[ellipsoidal, 2], 
	AXIS["Latitude (lat)", north, 
		ORDER[1]], 
	AXIS["Longitude (lon)", east, 
		ORDER[2]], 
	ANGLEUNIT["Degree", 0.0174532925199433], 
	ID["EPSG", "4045"]]

Data from @esri/proj-codes

{
  "wkid": 4045,
  "latestWkid": 4045,
  "macro": "PE_GCS_EVEREST_DEF_1975",
  "name": "GCS_Everest_def_1975",
  "wkt": "GEOGCS[\"GCS_Everest_def_1975\",DATUM[\"D_Everest_Def_1975\",SPHEROID[\"Everest_Definition_1975\",6377299.151,300.8017255]],PRIMEM[\"Greenwich\",0.0],UNIT[\"Degree\",0.0174532925199433]]",
  "wkt2": "GEOGCRS[\"GCS_Everest_def_1975\",DATUM[\"D_Everest_Def_1975\",ELLIPSOID[\"Everest_Definition_1975\",6377299.151,300.8017255]],PRIMEM[\"Greenwich\",0.0],CS[ellipsoidal,2],AXIS[\"Latitude (lat)\",north,ORDER[1]],AXIS[\"Longitude (lon)\",east,ORDER[2]],ANGLEUNIT[\"Degree\",0.0174532925199433],ID[\"EPSG\",\"4045\"]]",
  "description": "Everest (definition 1975)",
  "authority": "EPSG",
  "version": "4.5(8.1.0)",
  "deprecated": "no",
  "areaname": "Not specified",
  "extent": {
    "slat": -90,
    "nlat": 90,
    "llon": -180,
    "rlon": 180
  }
}