Applicability Of CMP 03

You have to pay tax on stock purchased from unregisrered dealer...... ...

if dealer opted composition w.e.f. 01-10-2017. CMP 03 Is applicable to him? and he has to pay tax on stock at which rate?

Please help me...

 

my client was registered in Punjab VAT under composition scheme and now again he opts composition scheme. is he liable to file the CMP 03
and let me know one thing more as my client was registered earlier under composition scheme so he didn't receive any input tax credit than how to fill form purchases including VAT or Purchase and VAT separately.