A Target Price Delta is an absolute number that acts as a target price for the OCO (one-cancels-other) position.

For example - 

A buy OCO order is placed for Reliance-EQ with

Quantity: 100

Limit price: ₹2000

Target Stop-Loss: 50

Stop-Loss Delta: 30

 

This means your buy order with a quantity of 100 shares would get traded at ₹2000 and automatically a Target Sell order would get generated for the quantity of 100 shares at

Target Sell order: (Buy order traded price + Target Price Delta) i.e. (₹2000+50) = ₹2050.