#### Answer

OR=4$\sqrt 3$$\approx$6.9

#### Work Step by Step

RV=2m$\angle$S
RV=2(15)=30$^{\circ}$
m$\angle$ROT=RV
m$\angle$ROT=30$^{\circ}$
m$\angle$OTR=90$^{\circ}$
OTR is a 30 60 90 triangle.
TR=$\frac{TO}{\sqrt 3}$
TR=$\frac{6\sqrt 3}{3}$
TR=2$\sqrt 3$
OR=2TR
OR=4$\sqrt 3$$\approx$6.9