牢 is a Japanese kanji written with 7 strokes, listed here under the keyword “jail”. It is built from 牛 (cow) and 宀 (roof). In Remembering the Kanji by James W. Heisig it is frame 2325.
On KumiJi Glyph Explorer, open the parts search and type “cow” + “roof”. 牢 is among the results, together with every other character containing the same shapes.
Open 牢 in the interactive kanji search
to expand every part down to its smallest pieces, add your own names and mnemonic stories,
or search for other characters by their parts.