Clear["Global`*"];
f[r_] = -((0.5 Sqrt[(-0.008 + 0.08 r^2 - 3. r^3 + r^4)/
r^4] (-0.0000853333 + 0.00128 r^2 - 0.024 r^3 -
0.0170667 r^4 + 0.36 r^5 - 6. r^6 +
r^7) (0.00188562 Sqrt[2 - 0.016/r^4 + 0.16/r^2 - 6/r] -
0.0282843 Sqrt[2 - 0.016/r^4 + 0.16/r^2 - 6/r] r^2 +
1.41421 Sqrt[2 - 0.016/r^4 + 0.16/r^2 - 6/r] r^3 -
0.707107 Sqrt[2 - 0.016/r^4 + 0.16/r^2 - 6/r] r^4 +
1. r^5 Sqrt[(0.00533333 - 0.04 r^2 + r^3)/
r^6] Sqrt[(0.00533333 - 0.04 r^2 + r^3)/
r^4] Sqrt[(-0.008 + 0.08 r^2 - 3. r^3 + r^4)/
r^4]))/(Sqrt[(0.00533333 - 0.04 r^2 + r^3)/
r^4] (-0.008 + 0.08 r^2 - 3. r^3 + r^4)^3));
int[mu_]int[mu_?NumericQ] := NIntegrate[f[r], {r, 5.93999, mu}]
Plot[int[mu], {mu, 5.93999, 8}, AxesOrigin -> {0, 0}]
Or
Clear[F];
F = NDSolveValue[{y'[mu] == f[mu], y[5.93999] == 0}, y, {mu, 5.93999, 8}];
Plot[F[mu], {mu, 5.93999, 8}, AxesOrigin -> {0, 0}]