IRCC accepts the following language assessment tests for immigration purposes:
Your test scores are then assessed against Canadian Language Benchmark (CLB). The following is the conversion table for IELTS to CLB:

CLB LevelListeningReadingWritingSpeaking
11.01.01.0
1.0
22.01.52.02.0
33.52.5
3.0
3.0
44.53.54.0
4.0
5
5.0
4.0
5.0
5.0
6
5.5
5.0
5.5
5.5
7
6.0
6.0
6.0
6.0
8
7.5
6.5
6.5
6.5
9
8.0
7.0
7.0
7.0
10
8.5
8.0
7.5
7.5
11
9.0
8.5
8.0
8.0
12
9.0
9.0
9.0
9.0