Need Solution

Your time is so less !!!

Go post in Bahrain forum so that they can advise you regarding practices prevalent there.

Additionally-

If you apply for a new passport (it's always a new passport when expiring and never a validity extension stamp on the passport), the Indian Government cancels your old passport and issues you a new one. Also returs you your old passport.

The new passport contains the number of your old passport.  This number of yoyr previous passport is your important link to all your visas on your old passport.

My passport was full with stamps and all pages were filled out without anu space for new stamps or for any additional visas that I required... so I needed a new passport... the old passport has valid long term multi entry visas for U.S.A. (10 year), Canada (7-1/2 years), U.K. (5 years), Shenegan (current again 1 year and still many months to go..) All of the above countries accept the visas as valid when both the passports are presented together at passport control/border as they already have your biometrics data. They look closely each time.., & I have had no problems in going to either USA or Canada with stopovers in London or a Shenegan country airport (whichever suits my convenience...)

So.. I suppose the same would be the case with Bahrain.. but, all the same ine should check and double check as it's a matter of livelihood.. especially because in my case the countries are mature with practicalities and have vast datas at their disposal to check a traveller... but my experience has been- the smaller a country (or say less developed with resources available to the government), the more finicky and impractical their visa and birder checks modalities  !!!😐

Wish you good luck with your research  ! Hope all turns out well for you ☺

Cheers !