A recent DCGI order restricted investigators from not conducting more than 3 trials? What does this mean?

The restriction means that a site can not undertake more than 3 trials irrespective of whether the trial is in recruitment or follow-up phase.

In some of the audits conducted by US FDA non compliance of Ethics Committee led a 483 issues to the principal investigator. As per US FDA inspector it is the responsibility of investigator to ensure that EC is compliant. Please opine.
As per ICH GCP 5.11.1 the sponsor should obtain from the investigator/institution:
(a)    The name and address of the investigator's/institution’s IRB/IEC.
(b)    A statement obtained from the IRB/IEC that it is organized and operates according to GCP and the applicable laws and regulations FDA regulations [21 CFR 312.23(a)(1)(iv)] require that a sponsor assure the FDA that a study will be conducted in compliance with the informed consent and IRB regulations [21 CFR parts 50 and 56]. This requirement has been misinterpreted to mean that it is a sponsor's obligation to determine IRB compliance with the regulations. This is not the case. Sponsors should rely on the clinical investigator, who assures the sponsor on form FDA-1572 for drugs and biologics or the investigator agreement for devices that the study will be reviewed by an IRB. Because clinical investigators work directly with IRBs, it is appropriate that they assure the sponsor that the IRB is functioning in compliance with the regulations.

Can investigator provide a copy of Ethics Committee SOPs or other documents to other departments in case query?

If anyone wants EC SOPs, they have to obtain the SOPs from the EC. See ICH 3.4 The IRB/IEC may be asked by investigators, sponsors or regulatory authorities to provide its written procedures and membership lists.

Can a product to export from India as a ‘New Chemical Entity’ without a license (for use in clinical trials in Europe)? If so what are the implication for the IMPD?
The IMPD includes summaries of information related to the quality, manufacture and control of the Investigational Medicinal Product, Data from non-clinical studies and from its clinical use. An overall risk-benefit assessment, critical analyses of the non-clinical and clinical data in relation to the potential risks and benefits of the proposed study have to be part of the IMPD. As IMPD is only information on IMP, there does not seem to be any license required for preparing IMPD.

Most of the CROs consider EC as vendor and vendor evaluation in form of periodic audit is performed by investigator team and quality assurance. Is this the correct approach?

EC is not a vendor. Hence, none can audit EC routinely, unless EC wants to be audited. However, you need to check with CDSCO and EMA whether you need an export license for exporting an NCE outside India.

What is coercion and undue influence in informed concept process?
According to the Belmont Report, “Coercion occurs when an overt threat of harm is intentionally presented by one person to another in order to obtain compliance. Undue influence, by contrast, occurs through an offer of an excessive, unwarranted, inappropriate or improper reward or other overture in order to obtain compliance.”