Letter Series Pattern

Look at numerical positions and case alternation:

• T (20, upper)
• r (18, lower): $-2$
• O (15, upper): $-3$
• m (13, lower): $-2$
• J (10, upper): $-3$

The pattern alternates subtracting $2$ and $3$. The next operation is $-2$: $10 - 2 = 8\text{th letter, lowercase} \implies h$