If it's just one or more of the hoses leading to your rack and pinion that has developed a leak then those hoses on the rack and pinion could be replaced with new ones to fix the leak.
But if it's actually the seals in the rack and pinion leaking then no it's not possible to repair the leaking seals on the rack and pinion.
You'll need to have the rack and pinion completely removed and then replaced with a new one.
A rack and pinion replacement can cost from $800.00 to $1,500.00 for parts and labor depending on the make and model of your vehicle and the shops hourly rates.