I want to create dvd using .mpg or .avi with Nero SDK, but could not find proper API. So please tell me how to. Thanks.
I assume you are speaking about creating DVD-Video?
There is no special API for this. You have to prepare the files for the DVD-Video yourself. Then you can burn a UDF/ISO filesystem to DVD which has to contain all necessary files on the necessary location.
The only thing that is special for DVD-Video is, that you should add the flag NCITEF_DVDVIDEO_REALLOC when calling NeroCreateIsoTrackEx.