import re
text = "Transport Department Government of NCT of Delhi\nLicence to Drive Vehicles Throughout India\n\nLicence No. : DL-0820100052000 (P) R\nN : PARMINDER PAL SINGH GILL\n\n: SHRI DARSHAN SINGH GILL\n\nDOB: 10/05/1966 BG: U\nAddress :\n\n104 SHARDA APPTT WEST ENCLAVE\nPITAMPURA DELHI 110034\n\n\n\nAuth to Drive Date of Issue\nM.CYL. 24/02/2010\nLMV-NT 24/02/2010\n\n(Holder's Sig natu re)\n\nIssue Date : 20/05/2016\nValidity(NT) : 19/05/2021 : c\nValidity(T) : NA Issuing Authority\nInvCarrNo : NA NWZ-I, WAZIRPUR"
search_phrases = ['Issue Date', 'Licence No.', 'N', 'Validity(NT)']
reg = r"\b({})\s*:\W*(.+)".format( "|".join(sorted(map(re.escape, search_phrases), key=len, reverse=True)) )
print(reg)
print(re.findall(reg, text, re.IGNORECASE))

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