R11 Version ( General Release )
Latest:

RM502QAEAAR11A04M4G_01.203.01.203

Older in no particular order:

RM502QAEAAR11A04M4G_01.202.01.202

RM502QAEAAR11A04M4G_03.202.03.202

RM502QAEAAR11A04M4G_01.201.01.201

RM502QAEAAR11A04M4G_01.200.01.200h

R13 Version ( Not general release, but can be tested )
Latest:

RM502QAEAAR13A04M4G_01.202.01.202

Older in no particular order: 

RM502QAEAAR13A04M4G_01.201.01.201.zip

RM502QAEAAR13A04M4G_01.200.01.200.zip

RM502QAEAAR13A03M4G_01.001.01.001

RM502QAEAAR13A02M4G_01.001.01.001

R11 Version (General Release)
Latest (March 2024):

RM500QAEAAR11A02M4G_01.200.01.200 

Older in no particular order:

RM500QAEAAR11A03M4G_01.200.01.200

RM500QAEAAR11A03M4G_01.001.01.001

R13 Version ( Not general release, but can be tested):
Latest (July 2023):

RM500QAEAAR13A03M4G_01.200.01.200.zip

RM500QAEAAR13A01M4G_02.003.02.003

RM500QAEAAR13A02M4G_01.200.01.200

Older in no particular order:
RM500QAEAAR13A02M4G_01.001.01.001

Quectel_RG50xQ&RM5xxQ_Series_AT_Commands_Manual_V1.2.pdf

Quectel_RM50xQ_Series_CA&EN-DC_Features_V1.6

Quectel_RM50xQ_Series_Hardware_Design_V1.2

Quectel Modem QFlash V7.0

Quectel Modem QFlash V6.9

Quectel Modem QFlash V6.4

Quectel Modem QFlash V6.5

Quectel_Windows_USB_Driver(Q)_ECM_V1.0

Quectel_Windows_USB_Driver(Q)_MBIM_V1.3

Quectel_Windows_USB_Driver(Q)_NDIS_V2.7

Quectel_Windows_USB_Driver(Q)_RNDIS_V1.1

Quectel Windows USB Drivers v2.3

Quectel Modem Update in openWRT – Wireless Haven Guide

Quectel Modem Update Firmware in openWRT and General Tutorials Wireless Haven Video