NAD 1983 CSRS MTM 6 - EPSG:2948

WKT

PROJCS["NAD_1983_CSRS_MTM_6", 
	GEOGCS["GCS_North_American_1983_CSRS", 
		DATUM["D_North_American_1983_CSRS", 
			SPHEROID["GRS_1980", 6378137.0, 298.257222101]], 
		PRIMEM["Greenwich", 0.0], 
		UNIT["Degree", 0.0174532925199433]], 
	PROJECTION["Transverse_Mercator"], 
	PARAMETER["False_Easting", 304800.0], 
	PARAMETER["False_Northing", 0.0], 
	PARAMETER["Central_Meridian", -67.5], 
	PARAMETER["Scale_Factor", 0.9999], 
	PARAMETER["Latitude_Of_Origin", 0.0], 
	UNIT["Meter", 1.0]]

WKT2

PROJCRS["NAD_1983_CSRS_MTM_6", 
	BASEGEOGCRS["GCS_North_American_1983_CSRS", 
		DATUM["D_North_American_1983_CSRS", 
			ELLIPSOID["GRS_1980", 6378137.0, 298.257222101]], 
		PRIMEM["Greenwich", 0.0], 
		CS[ellipsoidal, 2], 
		AXIS["Latitude (lat)", north, 
			ORDER[1]], 
		AXIS["Longitude (lon)", east, 
			ORDER[2]], 
		ANGLEUNIT["Degree", 0.0174532925199433]], 
	CONVERSION["Transverse_Mercator", 
		METHOD["Transverse_Mercator"], 
		PARAMETER["False_Easting", 304800.0], 
		PARAMETER["False_Northing", 0.0], 
		PARAMETER["Central_Meridian", -67.5], 
		PARAMETER["Scale_Factor", 0.9999], 
		PARAMETER["Latitude_Of_Origin", 0.0]], 
	CS[Cartesian, 2], 
	AXIS["Easting (X)", east, 
		ORDER[1]], 
	AXIS["Northing (Y)", north, 
		ORDER[2]], 
	LENGTHUNIT["Meter", 1.0], 
	ID["EPSG", "2948"]]

Data from @esri/proj-codes

{
  "wkid": 2948,
  "latestWkid": 2948,
  "gcsWkid": 4617,
  "macro": "PE_PCS_NAD_1983_CSRS_MTM_6",
  "name": "NAD_1983_CSRS_MTM_6",
  "wkt": "PROJCS[\"NAD_1983_CSRS_MTM_6\",GEOGCS[\"GCS_North_American_1983_CSRS\",DATUM[\"D_North_American_1983_CSRS\",SPHEROID[\"GRS_1980\",6378137.0,298.257222101]],PRIMEM[\"Greenwich\",0.0],UNIT[\"Degree\",0.0174532925199433]],PROJECTION[\"Transverse_Mercator\"],PARAMETER[\"False_Easting\",304800.0],PARAMETER[\"False_Northing\",0.0],PARAMETER[\"Central_Meridian\",-67.5],PARAMETER[\"Scale_Factor\",0.9999],PARAMETER[\"Latitude_Of_Origin\",0.0],UNIT[\"Meter\",1.0]]",
  "wkt2": "PROJCRS[\"NAD_1983_CSRS_MTM_6\",BASEGEOGCRS[\"GCS_North_American_1983_CSRS\",DATUM[\"D_North_American_1983_CSRS\",ELLIPSOID[\"GRS_1980\",6378137.0,298.257222101]],PRIMEM[\"Greenwich\",0.0],CS[ellipsoidal,2],AXIS[\"Latitude (lat)\",north,ORDER[1]],AXIS[\"Longitude (lon)\",east,ORDER[2]],ANGLEUNIT[\"Degree\",0.0174532925199433]],CONVERSION[\"Transverse_Mercator\",METHOD[\"Transverse_Mercator\"],PARAMETER[\"False_Easting\",304800.0],PARAMETER[\"False_Northing\",0.0],PARAMETER[\"Central_Meridian\",-67.5],PARAMETER[\"Scale_Factor\",0.9999],PARAMETER[\"Latitude_Of_Origin\",0.0]],CS[Cartesian,2],AXIS[\"Easting (X)\",east,ORDER[1]],AXIS[\"Northing (Y)\",north,ORDER[2]],LENGTHUNIT[\"Meter\",1.0],ID[\"EPSG\",\"2948\"]]",
  "description": "NAD 1983 CSRS MTM  6",
  "authority": "EPSG",
  "version": "6.15(9.3.0.0)",
  "deprecated": "no",
  "areaname": "Canada - Quebec and Labrador - 69~W to 66~W",
  "extent": {
    "slat": 47.31,
    "nlat": 59,
    "llon": -69,
    "rlon": -66
  }
}