Clarification required about GST reg

Sir,

1.One of my relation is doing Medical Retail business.
2.His yearly turnover not crossing Rs.15 Lakhs.
3. So he no need to register for GSTIN.
4. But his distributors is asking GSTIN for his medical shop.
Then only his distributors can raise the Invoice for his Medicalshop..

My query is :

if he register his business under GST, whether he is able to get Input Tax Credit ? Since his business yearly turnover comes Rs.15 Lakhs.

He is selling the medicines only to end customers not for other dealers.

pl reply.

Thank you.

Regards,
R. Marimuthu