What is the video codec name of videos made through the Canon 600d DSLR
All Canon DSLRs, including 600D use the same video codec: 


Codec: MPEG-4 Part 10 / AVC / H.264
Profile: Baseline
Level: 5.0
Bitrate mode: CBR ± 40 Mbit/s maximum average
PAL: 1080p25, 1080p24, 720p50, 480p50
NTSC: 1080p30, 1080p24, 720p60, 480p60 
Colorspace: 8-bit YUV 4:2:0 Rec. 709


Many of the higher-end models have an additional All-I mode:


Profile: High (without CABAC)
Level: 5.1
Bitrate mode: VBR ± 100 Mbit/s maximum average