So I found some ways in saying arrowhead but found various. One is 矢じり 「やじり」 and the other one is 石鏃 「せきぞく」 Honestly I got confused with the two. Is 矢じりa Japanese arrowhead or any kind? same question for 石鏃。
The word recognized by laypeople is 矢じり. People simply say 矢の先端, too.
石鏃 is a technical term for "arrowheads made of stone" as the kanji 石 suggests. See this Wikipedia article. This 鏃 (on: ソク/ゾク, kun: やじり) is a single-character kanji for "arrowhead", but this is not a joyo kanji and most people cannot read it without furigana. Arrowheads made of iron are specifically called 鉄鏃.