Yes. You should go for 5w-30 API SN fully synthetic motor oil.
On Shell Global website, variety of fully synthetic API SN engine oils are available ( https://www.shell.com/motorist/oils-lubricants/helix-for-cars/helix-fully-synthetic.html ), however on Shell Pakistan website, only 03 Fully synthetic API SN grades are available:
5w-20, 5w-40 and 0w-20
( https://www.shell.com.pk/motorists/oils-lubricants/helix-for-cars/helix-fully-synthetic.html )
I think, Shell 5w-30 Fully synthetic API SN motor Oil is not offered / available in Pakistan officially, or at least, as per their website. If it's available in the market, then there could be two possibilities; either the website is not updated (which is highly unlikely) or Shell 5w-30 Fully Synthetic API SN oil is available through some grey / illegal channels or it may be Fake altogether.
I think, the only good and reliable options available are either Total Quartz 9000 or Eneos Sustina.
For complete previous engine oil flushing, please refer to this product by Liqui Moly:
http://www.liqui-moly.com.pk/engine-flush
And regarding performance on 5w-40, abhi shayed aapnay 5w-30 kabhi use Kar k nai daikha
Aik dafa 5w-30 use Karein and performance daikhein
Aap 5w-40 hameesha k liay bhool jyein gey 