Hello and welcome to HCM.
As an 
Urologist,i can understand your concern.
A 6mm stone,can be treated with medication after doing some tests like :
1. urine routine and culture.
2. blood routine,
creatinine,uric acid,RBS,LFT,calcium,and phosphorus test.
3. 24 hours urine for calcium,phosphorus and uric acid test done.
Drink about 15 glasses fluids,excluding milk, daily.
Start potrate magnessium citrate tablets twice daily.Show reports to Urologist. You may send reports to me,as a direct question to me.
Dr.Matthew J. Mangat.