The right pronunciation of [r] sound is very important. Imagine that there are many many Russian words with this sound, some of them contain several r’s inside, so you have to pronunce it perfectly to sound like a real Russian.
To make an r sound tap the tip of your tongue against the area behind the top teeth. Like this:
The sound should be voiced and quite loud. Try to pronounce it several times. If you feel the vibration inside your mouth, it means you’re doing this right. Keep going. And practice some Russian words with the letter “r”:
Россия, работа, рот, река, ртуть, рупор, переговоры, репортер, территория.
And finally the hardcore word – перерегистрировать.
Listen to the audio to check if you pronounce this sound correctly: