Which Republic arms model do you own?
Ether a photo or a model number will help. Since they don't make a 1911 that cant be the gun.
I think asking a good gunsmith is the best choice but since its not a very big company from Africa you may not have much luck no mater what you do.
If you can shair a photo of the broken aria we might be able to help more.
Is it the Patriot 45 DOA?
If this is the gun you own then depending on what and where was broken the receiver is not repairable since it’s a one piece polymer lower.
RAP-440
.40 S&W cal., compact DA/SA, 3 1/2 in. barrel with high contrast 3-dot sights, last shot hold open, hammer drop safety/decocking lever, firing pin block safety, 7 shot mag., all steel construction, 31 1/2 oz., includes case, spare magazine, and lock. Imported 1998-circa 2002.
THE PATRIOT
.45 ACP cal., DAO, ultra compact with 3 in. barrel, 6 shot mag., ultra compact black polymer frame and stainless steel slide (either brushed or with black Melonite coating, new 2000), locked breech action, checkered grips, 20 oz. Mfg. 1997-2001.
M88A
9mm Para. cal., 3.78 in. hammer forged barrel and slide, includes two 8 shot mags., checkered polymer grips, external safety, blue finish. Importation began 2014.
GENERAL
.45 ACP, 9mm Para., 10mm, .38 Super, or .40 S&W cal., Officer frame (.45 ACP cal. only), 3 1/2 in. barrel, 25 LPI checkering on front strap, serrations on top of slide, color coordinated VZ grips (Standard frame or Magwell frame only), choice of finish.
DEFIANT
.45 ACP, 9mm Para., 10mm, .38 Super, or .40 S&W cal., Commander frame, Officers slide, 3 1/2 in. barrel, knurling or 25 LPI checkering on front strap, serrations on top of slide, color coordinated VZ grips, choice of finish.