Received unwanted call from a unknown number

Sir
My sister got a call from a unknown number claiming that they are from telenor India new Delhi office and told that my sister’s number have won 25 lakh rupees from a lottrey but I not trusted them when I asked them is your lottery is registered by central government of India so they don’t gave me proper answer so I thinker that they are fraud their number is +923053122993 sir please investigate who they are