import re
p = re.compile(r'/\* *Custom-D Start *\*/\s*(.*?)/\* *Custom-D End *\*/', re.DOTALL)
test_str = "/* Highlighting edits text on TIB ONLY and NOT ON PDF Output. \n   .main-igp selector makes this style apply only for TIB.  */\n.main-igp .edit1 {color: rgb(235, 127, 36)}\n.main-igp .edit2 {color: rgb(0, 0, 180);}\n/*Custom-D Start     */\n.main-igp .edit3 {color: rgb(0, 180, 180);}\n.main-igp .edit6 {color: rgb(200, 200, 0);}\n/* Custom-D End */\n/* Production Note ===== */\np.production-note-rw {\n    display: none;}\n/* Production Note END ===== */"
m = p.search(test_str)
if m:
	print(m.group(1))

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