Dear Swagata Chakraborty ,

I am not a chemist, but this is basic percent calculation...

Let us first check, whether your envisaged '60%' of Sodium Iodine solution is able to be reached at all with respect to the Sodium Iodine solubility in water.

According to chapter '3.2.7 Solubility' of

https://pubchem.ncbi.nlm.nih.gov/compound/5238#section=Solubility

the solubility of NaI (i.e. for example the largest amount of NaI in 100ml of water) is 184g (at 25°C) in 100g of water.

The concentration cs (by weight) in this case is cs = 184/(184+100)=64,8%

So, you see, that you should be able to dissolve NaI up to your envisaged concentration of 60%.

So just do it...

for example you may

a) take 60g of NaI and add 40g (=40ml) of water

c = 60/(60+40) = 60% , or

b) 600g of NaI and add 400g (=400ml) of water

c = 600/(600+400) = 60%

Final remark:

you are close to the solubility; so dissolving all you material will take a lot of time; but you could do the dissolving at elevated temperatures...

Good luck and

best regards

G.M.