issue of legal notice

Yes sir. certainly, you can.

As an advocate, you are aware of the fact that issuing such legal notice is fundamental as the reply notice serves as admissions or denials to prepare plaint suitably.  It appears that your clients may be of Finance companies or private lenders and wanted to use the notice to bring pressure or a threat to borrowers.  Your clients may be under the impression that those borrowers will get frightened and come to repay the amounts.  There is nothing wrong in agreeing with the client's notice.

In the following link, there is such a well-crafted format of notice and you can modify the notice to suit your requirements. https://www.lawyersclubindia.com/forum/bajaj-finance-personal-loan-218682.asp

Certainly you can. But what is the context for your doubt?

I endorse the advise of experts, you can issue legal notice on behalf of your clients

As per your query, let me tell you that a legal notice is essentially a notice sent by an advocate on the behalf of his/her client. It has nothing to do with your specialization (be it taxation, criminal or civil). Thus, you're free to send the notice, there's no issue in that.

Regards
Kevin M. Paul

sir. I would like to further update in continuation with the above info that I have passed my LLB in the year 2018 and got enrolled with the bar council of the state of telangana, Hyderabad on 14/02/2019, hence I am holding right now provisional certificate of enrollment as advocate and all India bar exam is yet to pass.
now my doubt is after giving the notice to the client, if situatuon warrants to make a civil suit, can I also file the civil suit and appear before the court of law. because I am not holding the certificate of practice. kindly advise.

You have enrolled on 14-02-2019.  The license will be issued for 5 years and before completion of the 5th year that means after completion of period 4 years and 6 months you have to submit an application for renewal of practice.  So you can file and can argue.