Can anyone help me to get via on a single net if it is inside the BGA premises. Thanks.
It is possible if the via have a connection to the BGA. but if the via have no connection to the bga, you have to extract dbid of the bga from list of the design symbols. you can use:
designSymbols = axlDBGetDesign()->symbols -> list of all symbols in your design.
after getting the list, you can now filter BGA symbols depending on unique characteristic of BGA.