Income tax related quarries

Dear sir 

I have following 3 quarries...

1) My son has opened HUF bank account . He has deposited 6 lakh from his own fund and invested in mutual fund .. in 2017-18 their is no income exept 5000 interest .. no short term or capital income .. whether it is necessary to file return of HUF. .?

2) In form 16 of my son HRA exmption shown by employer is 60000 as against actual comes to 124000.. Can i  claim actual exmption while filling return ? 

3) my wife had Long term capital gain of 7 lakh during 2017-18 which is tax free .. and other income bank interest is 2 lakh which is below then tax limit .. is it necessary to file return ? 

Please send u r reply by email at an earliest so that i van file return ..



Kg shah