Row is 5, column is 5, how to give command for

If I have 5 different drugs and to see its effect on the paw volume of rats in 5 different days, each group has 6 animals .how to make a data set for R. 5 treatment groups with 6 animals in each and observation taken 5 times .eg. Drug A,B,C,D,E each having 6 members to receive the drug, reading of paw vol taken on day 0,4 8 14 and 21 days and mean of diff group is compared to see which drug works better than the other. How to prepare excel sheet and how to give command in R for my prepared data to see in box plot.

Welcome @Rajlaxmi in this group.

I would not make it more complicated than it is.
Below you see a simple setup for your problem (as I understand it).

Use the functions write.csv and read.csv to move the data to and from a csv file (and from there into Excel).
If all your data is available you can use the boxplot function in R.

Use the help info if need more help with a function: just type ?functionname .

Enjoy and good luck.

df1= data.frame(
  Animal = 1:30,
  Drug= rep(c('A','B','C','D','E'),6),
  Day0=rep(NA,30),
  Day4=rep(NA,30),
  Day8=rep(NA,30),
  Day14=rep(NA,30),
  Day21=rep(NA,30)
)
print(df1)
#>    Animal Drug Day0 Day4 Day8 Day14 Day21
#> 1       1    A   NA   NA   NA    NA    NA
#> 2       2    B   NA   NA   NA    NA    NA
#> 3       3    C   NA   NA   NA    NA    NA
#> 4       4    D   NA   NA   NA    NA    NA
#> 5       5    E   NA   NA   NA    NA    NA
#> 6       6    A   NA   NA   NA    NA    NA
#> 7       7    B   NA   NA   NA    NA    NA
#> 8       8    C   NA   NA   NA    NA    NA
#> 9       9    D   NA   NA   NA    NA    NA
#> 10     10    E   NA   NA   NA    NA    NA
#> 11     11    A   NA   NA   NA    NA    NA
#> 12     12    B   NA   NA   NA    NA    NA
#> 13     13    C   NA   NA   NA    NA    NA
#> 14     14    D   NA   NA   NA    NA    NA
#> 15     15    E   NA   NA   NA    NA    NA
#> 16     16    A   NA   NA   NA    NA    NA
#> 17     17    B   NA   NA   NA    NA    NA
#> 18     18    C   NA   NA   NA    NA    NA
#> 19     19    D   NA   NA   NA    NA    NA
#> 20     20    E   NA   NA   NA    NA    NA
#> 21     21    A   NA   NA   NA    NA    NA
#> 22     22    B   NA   NA   NA    NA    NA
#> 23     23    C   NA   NA   NA    NA    NA
#> 24     24    D   NA   NA   NA    NA    NA
#> 25     25    E   NA   NA   NA    NA    NA
#> 26     26    A   NA   NA   NA    NA    NA
#> 27     27    B   NA   NA   NA    NA    NA
#> 28     28    C   NA   NA   NA    NA    NA
#> 29     29    D   NA   NA   NA    NA    NA
#> 30     30    E   NA   NA   NA    NA    NA

Created on 2020-08-01 by the reprex package (v0.3.0)