Form 121 in case of income below 4 lakhs, plus LTCG of 3 lakhs

My wife's annual income is below 4 lakhs, so thinking of submitting form 121 with Bank,

Now, in case she want to sell shares there will be LTCG of another 3 lakhs 

Can she submit form 121 with Bank

As far as I know, one can submit form 121 if income tax liability is zero.

My question is whether above-mentioned zero tax liability is inclusive of LTCG .

Thanks