The description for the CCPTMRS register is missing in the data sheet. The description for this register is mentioned below.
Each CCP/PWM module has an independent timer selection that can be accessed using the CxTSEL or PxTSEL bits. The default timer selection is TMR1 when using Capture/Compare mode and TMR2 when using PWM mode in the CCPx module. The default timer selection for the PWM module is always TMR2.