Will I get into the Heritage Institute of Technology with a 20k rank in the WBJEE?

The rankings depend on the recently produced cut off by the institute, so as to process admission. By the rank you have secured, it is quite apparent that you can get an admission seat for the Biotechnology branch. 

Here is a breakdown of the cut-off (opening and closing) recently produced by the institute.

However, at times, it can take you until the last round to get shortlisted. In any case, it is generally difficult for a general student to acquire admission at Heritage Institute of Technology with a rank of 20,000. But, it is best that you still research more about the latest cut-off trends.