how can i find my iphone

hello sir/mad

i lost my mobile iphone 6plus... and after that try to coonect wth my iphone. its not possible to connect and i used icloud for find my iphone..

but the main problem is when i check its offline......how can i find my phone...

serial no.; FK******5QY

IF U CAN POSSIBLE TO TRACK THIS IPHONE PLEASE HELP ME

how can people r use and open apple id without password.....

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