Generally, being able to study an IELTS textbook requires understanding at least 70% of the vocabulary and sentence structures, which corresponds to roughly an IELTS 3.5 level.
If your current score is IELTS 2.0, we recommend starting with ESL or IELTS BASIC for the first 4–6 weeks. For ESL, the Spartan Program is particularly effective for building a strong foundation.
Once you reach approximately IELTS 3.5, you can move on to the IELTS Intensive course for full-scale IELTS preparation. The total study period to reach IELTS 6.5 from your current level is estimated to be about 24 weeks.