1. Yes

2. Yes

3. Yes

4. Section 188 of crpc and now section 208 of BNSS governs this issue. 

Generally it’s very difficult to again initiate the trial for same offence already convicted in foreign soil. You need sanction from central govt. Only if offence is distinct then same can be tried

As the alleged offence took place outside India, the accused cannot be tried under Indian law for want of territorial jurisdiction. Moreover, one of the fundamental principles of criminal law is that no one can be punished twice for the same offence.

Your friend can initiate criminal proceedings in India against her ex-boyfriend if he is an Indian citizen. Indian law provides extra-territorial jurisdiction for offenses committed by Indian citizens abroad.

Under Section 1(4) of the BNS, the provisions of Indian penal law apply to any offense committed by any citizen of India in any place outside India.  Under Section 208 of the BNSS  an Indian citizen who commits an offense outside India can be investigated and tried at any place in India where he is found.  While the police can register an First Information Report (FIR) and conduct an investigation, no court in India can proceed to try the case without prior sanction from the Central Government of India (Ministry of Home Affairs).

Under Section 209 of the BNSS, the Central Government can direct that certified copies of depositions, statements, or exhibits produced before judicial or police authorities in a foreign territory be received as evidence in Indian courts. Screenshots, voice recordings, and emails will need to be certified under Section 63 of the Bharatiya Sakshya Adhiniyam, 2023 (BSA) to establish proof of electronic records and chain of custody. Copies of evidence verified or attested by the Indian High Commission in the UK or directly obtained via the UK police report will carry substantial evidentiary weight.

Article 20(2) of the Indian Constitution and Section 337 of the BNSS ) bar a person from being prosecuted twice for the same offense (double jeopardy). However, this applies only if the person was formally tried and convicted or acquitted by a judicial court of law.

Depending on the exact nature of the harassment, the charges under the Bharatiya Nyaya Sanhita (BNS) and Information Technology Act, 2000 may apply.

She can lodge a written complaint at the jurisdictional police station in India where the accused resides, or file a Zero FIR at any police station/online police portal, which will then be transferred to the local station.

1. Can an FIR/complaint be filed in India?
Yes. Under Section 4, Bharatiya Nyaya Sanhita (BNS) [earlier IPC Section 4], Indian courts have extraterritorial jurisdiction over offences committed by an Indian citizen abroad. However, prosecution requires prior sanction of the Central Government under the BNSS provision corresponding to old CrPC Section 188 (please verify the current section number before filing, as BNSS renumbering should be double-checked). The complaint/FIR can be filed where the accused is currently found/resides in India, or where your friend resides.

2. Can UK evidence be used in India?
Yes, in principle — voice recordings, screenshots, and witness statements can be relied upon, but they will need to be properly authenticated/certified (translations, chain of custody, forensic certification under the Bharatiya Sakshya Adhiniyam equivalent of Evidence Act S.65B for electronic records). Certified copies of the UK investigation file can be sought via a Mutual Legal Assistance Treaty (MLAT) request through the Ministry of Home Affairs, which strengthens admissibility.

3. Does UK action bar Indian prosecution?
No. Deportation, visa cancellation, and university expulsion are administrative/immigration consequences, not criminal convictions. Double jeopardy (Article 20(2) of the Constitution / Section 300 CrPC-BNSS equivalent) applies only where there has been a conviction or acquittal by a competent court — not mere arrest or administrative action. Since no UK criminal trial/verdict has occurred (please confirm this), there is no legal bar to Indian proceedings.

4. Applicable law & process

• Likely provisions: sections under BNS dealing with sexual harassment, stalking, criminal intimidation, voyeurism (depending on exact facts — please specify which acts occurred, as sections will differ, e.g., sexual harassment provisions vs. stalking vs. outraging modesty).
• Process: (a) file a complaint with police or directly before a Magistrate under Section 175(3)/relevant BNSS provision if police don't register FIR; (b) simultaneously apply to MHA for sanction under the extraterritorial-jurisdiction provision; (c) request MLAT assistance for UK evidence certification.

This is procedurally more involved than a domestic case (sanction + evidence certification take time), but it is legally maintainable. I'd recommend we file a detailed representation to the police along with the sanction application simultaneously to avoid delay.

Thanks And Regards 
Adv. Aman Verma
Legal Corridor