Dear Mr. Rahul,
There are many ways, processes, and means of identifying the Training Needs. First of all, you should have job descriptions for all the individuals, then a Skill matrix part. By determining what is required and what the individual possesses - the gap will be one area. The second area is through the Performance Management System where the HOD should specify the needs, and the individual can also specify his needs to upgrade himself. The third one is the HOD's feedback. You can also talk to the internal customers and obtain inputs.
You can organize a training program on soft skills as a beginning, and there you can identify the gap regarding skill gap. In the current scenario, the basic thing I observed is that you need to organize a training program for your HODs on team building, employee development, and delegation.
I believe the above information will give you some idea about your query. Please feel free to contact me if you have any other requirements.
Thanks and regards,
Kameswarao