Snowflake Sudoku (Fun With Sudoku #10)

This puzzle first time appeared in World Sudoku Championship 2007 (Part 2). I made it for the practice of the Indian team in 2007. Now again this puzzle is appearing in World Sudoku Championship 2009 (puzzle C1).
Re-publishing this Snowflake Sudoku puzzle as 10th Sudoku of  Fun With Sudoku Series.

Rules of Snowflake Sudoku

Fill the grid so that every hexagon and every cell in all directions contains all the digits 1 to 6.

Snowflake Sudoku (Fun With Sudoku #10)

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The solution of Outside Killer Sudoku (Daily Sudoku League #77)

Outside Killer Sudoku (Daily Sudoku League #77) Solution