12000 MYR per month for a family of 2 to live in Kuala Lumpur

Please provide your Indian salary in RM The normal rule of thumb is double your Indian salary and exchange into RM as a minimum acceptable salary. COL is about 35% higher in Malaysia and if you want to send money back, the exchange rate is bombing.

In India I can save upto 5300 MYR.

About RM7-7.5k saving here I would guess. Butting getting money out of Malaysia with value will be difficult for some years to come due to exchange rate.

How? I got to know the taxes are flat 26% for initial 6 month which come to 3120 i.e. in hand now 12000-3120=8880 after that the COL in KL which is about 4k MYR i.e. 8880-4000 = 4880 MYR.

Correct my understanding if wrong.

Ii was working on normal tax rates not non-resident ones remembering over 1-2  tax years, the overpayment is refunded.

I will be in KL for an period of 1 year, so when will I get the overpayment refund amount?

Depends when you arrive, but as long as you do 182 days in one tax year you will get overpayment refunded. If you come say in October/Nov you still get the tax free allowance for that year.

0-5,000                    0%                                                 
5,000-10,000      1% = RM50
10,001-20,000    1%  = +RM100
20,001-35,000    5%  = +RM750
35,001-50,000   10%  = +RM1,500
50,001-70,000   16% = +RM3,200
70,001-100,000   21% = +RM6,300
100,001-144,000 24% = +RM10,560

The cost of accommodation is the deal breaker and not knowing where you will need to live, RM2k should be enough unless you need to be in KLCC. It can also be a lot lower in the more remote suburbs if you want to save more.

Thanks for the information.