I can use
getblock json rpc method to get parsed block, but I need raw data.
Is there any way to get raw block data using bitcoin core?
There's a boolean parameter to that RPC call that'll return it as a hex string representing the binary contents of the block.
If verbosity is 0, returns a string that is serialized, hex-encoded data for block 'hash'
getblock 'hash' 0 should return what you want.