pl can anyone tell me what course can i do after ll.b in india to start practising in USA

you cannot just start practising law in US if you are an Indian citizen and living in India currenty and I am not aware of any special course taht you can take in India for this purpose.

the best option is to do an LLM in US and then write a bar exam here in US (some states like NY and CA allow foreign LLMs, whose primary law degree is not from US, to sit for their bar exams) and finally find a job in US.