2 week visit visa Indian national

Apply for an evisa. But they will need to show proof of funds to support themselves as well as return air ticket.  NOC or eNOC is for a sponsored visa which your employer will apply for on your behalf - no proof of funds needed in that case nor air ticket.

So as long as they have proof of funds they are good to go right? My mom has US visa too so I am thinking getting a Bahrain visa won't be a problem as long as she can show that she had enough funds in her bank to support her travel. What about minors? In this case my little sister, will she be able to piggy back on my mom's account and get her tourist visa as well without any problem? Tia.

If she is below 18, then yes.  Your mother needs to write a letter saying that she is travelling with her and will support her.   In the bank statement, there should be at least 300 BHD in equivalent currency and the statement should be stamped by the bank.

Conditions for Visit Single entry

The Visit Single entry is only granted subject to the following terms and conditions.

WARNING:

Holding a visa does not guarantee your entry to the Kingdom of Bahrain.You must meet all of the conditions on arrival to be granted the entry, at the discretion of an Immigration Officer.

Fees:

Application fee:    BD 4.000
Visa fee:    BD 5.000
Total fee:    BD 9.000 (payable on submitting the application)

Refund conditions:   
• The application fee is not refundable under any circumstances.
• The visa fee is not refundable.

Grant conditions:   
• The visa is issued on the Internet.
• The visa fee is paid on the Internet, and no receipt is issued.
• Your entry must not violate the security and national welfare of the Kingdom of Bahrain.

Validity conditions:   
• Validity is 30 days. This means the visa must be used within 30 days of approval.
• If the visa expires before entry to the Kingdom of Bahrain, the applicant must apply again, and another fee must be paid.

Entry conditions:   
• Applicant must not take up any paid or unpaid employment during the visit to Bahrain.
• You must be able to support yourself (and any dependents) during the visit.
• Passport must be valid for length of time you will be in Bahrain, or the length of the visa, whichever is longer.
If your passport validity is in doubt, you may be denied entry to Bahrain.

Stay conditions:   
• The visa can be used only once, for a single entry.
• Length of stay allowed is 2 weeks.

Extension conditions:   
• This visa can be extended at the Nationality, Passports and Residence Affairs office (NPRA) in the kingdom of Bahrain on payment of a fee.

Document conditions:     You must submit the following documents with your application:
1. Photocopy of the photo page of the applicant's passport plus a copy of the passport last page for Indian passports.
2. Copy of return air ticket.
3. Copy of hotel booking in Bahrain. Alternately, in case you are staying with a relative, please provide a copy of their CPR Reader's printout.
4. Copy of a stamped bank statement under the visitor's name covering the last three months with an ending balance of not less than the equivalent of BD300.

Optional document conditions:     You may optionally attach the following documents with your application:
1. Copy of GCC and/or any USA, Schengen, UK, European or Canadian visa.

https://www.evisa.gov.bh/index.html

2 week visit visa can be transfer to work visa
Or
2 week visit can extend upto how many month.

Can be transferred if application is filed 6-7 working days before expiry of visa.