library(leaflet)

data_frame<-data.frame(lat = runif(20, min = 28.628151, max = 28.628151),
                 lng = runif(20, min = 77.367783, max = 77.367783))

Icon <- makeIcon(
  iconUrl = "location-icon.png",
  iconWidth = 31*215/230, iconHeight = 31,
  iconAnchorX = 31*215/230/2, iconAnchorY = 16
)
data_frame %>% 
 leaflet() %>% 
  addTiles() %>%
  
addMarkers(clusterOptions = markerClusterOptions(),popup ="IBM office",icon = Icon) %>%
addCircleMarkers(color = "red")
# Please click on the icon 20 written