Hi Ranjeet,
In order to understand the aforementioned parameters in OFDM components, please refer to the answer provided in the link I have addressed below, where I have asked the more or less the same question a while ago and here is Damian’s answer:
Please feel free to ask any further questions you may encounter. I suggest you also go through the help section of the component if you find the answer inadequate in any way (which I believe is quite comprehensive).
If you are using OS12 OFDM components, I suggest you choose the used subcarriers in between the available subcarriers, the way set in the examples provided.
Regards