hello friends I am gonna tell you about best phone in OPPO reno series for you . we do this comparision with some bases. first we see all models specification then we conclude our answer also we do not take pro or pro+ models and this is my personal opinion so lets start.

OPPO RENO 

                            
DISPLAY : 6.4 inches AMOLED display with corning gorilla glass 6 front and back is corning gorilla glass 5 . 
CAMERA : 48mp wide camera , 5mp (depth) with dual LED flash , HDR , Panorama .
                  Motorized pop up 16 mp wide selfie camera. 
CHIPSET : Qualcomm  snapdragon 710
RAM/ROM : 6gb,128gb/8gb,128gb/ 6gb,256gb /8gb, 256gb
OS : Android 9.0 (PIE) upgradable to Android 10 , COLOR OS 7.0
BATTERY : 3765 mAh non removable battery with 20W fast charging
                   VOOC
FEATURES : fingerprint ( under display , optical) , accelerometer , gyro , proximity . 
PRICE : 29,998 rupees / 598 $ 
  

OPPO RENO 2

                                
DISPLAY :6.5 inches AMOLED display with corning gorilla glass 6 front and corning gorilla glass 5 back . 
CAMERA : 48mp , 13mp , 8mp , 2mp with dual LED flash , HDR and also panorama
                Motorized pop up 16mp selfie camera with LED flash HDR
CHIPSET : Qualcomm snapdragon 730g
RAM/ROM : 8GB,128GB/8GB,256GB 
OS: Android 9.0 upgradable to Android 10 , Color OS 7.0 
BATTERY : 4,000mAh non removable battery with 20W fast charging
                 VOOC 3.0 
FEATURES : fingerprint ( under display , optical ) accelerometer , gyro , proximity .
PRICE  : 38,990 rupees / 598.30 $

OPPO RENO 3

                                      
DISPLAY : 6.4 inches AMOLED display
CAMERA : 48mp , 13mp , 8mp, 2mp with LED flash HDR panorama
                  44mp wide selfie camera with HDR
CHIPSET : Mediatek MT6779 Helio P90
RAM/ROM :8gb,128gb
OS : Android 10, Color OS 7
BATTERY : 4025mAh non removable battery with 30W fast charging
                  VOOC 3.0
FEATURES : fingerprint ( under display , optical ) proximity , accelerometer , gyro
PRICE : 38,785 rupees


OPPO RENO 4

                               
DISPLAY : 6.4 inches OLED display
CAMERA : 48mp , 8mp , 2mp , 2mp , with LED FLASH , HDR , Panorama
               32MP WIDE selfie camera with HDR
CHIPSET : Qualcomm SM7125 Snapdragon 720G
RAM/ROM : 8gb,128gb 
OS : Android 10, Color OS 7.2
BATTERY :  4015 mAh, non-removable battery with 30W fast charging
                 VOOC 4.0
FEATURES : fingerprint ( under display , optical ) proximity , gyro , accelerometer
PRICE : £ 329.99

OPPO RENO 5

DISPLAY : 6.43 inches AMOLED display with corning gorilla glass 5
CAMERA : 64mp , 8mp , 2mp ,2mp with LED flash , HDR , panorama
                  32mp wide selfie camera with HDR . 
CHIPSET : Qualcomm SM7250 Snapdragon 765G 5G 
RAM / ROM : 8GB, 128GB / 12GB, 256GB
OS : Android 11, Color OS 11.1
BATTERY : 4300mAh non removable battery with 65W fast charging
                super VOOC 2.0
FEATURES : fingerprint ( under display , optical ) accelerometer , gyro , proximity
PRICE : 35,599rupees / 479.99 $


OPPO RENO 6

DISPLAY : 6.43 inches AMOLED display with corning gorilla glass 5
CAMERA : 64 MP , 8MP , 2MP ,  LED flash , HDR , panorama
               32mp wide selfie camera with panorama
CHIPSET :MediaTek MT6877 Dimensity 900 5G 
RAM/ROM : 8GB,128GB/12GB,256GB
OS :Android 11, Color OS 11.3
BATTERY : 4300mAh non removable battery with 65W fast charging
                  super VOOC 2.0
FEATURES : fingerprint ( under display , optical ) accelerometer , gyro , proximity , color spectrum
PRICE : 31,890 RUPEES ( expected ) 


from my opinion the best reno series mobile for you is oppo reno 5 because it have all recent features and comes in 35,600 price range and if you want to buy this phone its quite good deal for you .