Integration of a fraction function by RootSum or Rubi

I’m trying to solve an integral of p[Tau,r] function:

Clear["Global`*"]
u[0, t_] = 1;
u[1, t_] = t;
u[n_, t_] := 2 *t*u[n - 1, t] - u[n - 2, t];
tableoft = tt /. NSolve[u[7, tt], tt]
x[t_] = Sum[Simplify[Subscript[a, j]*u[j, t]], {j, 0, 6}]
f[t_] = (t^4/6 - t^3/3 + t) /. t -> 1/2*([Tau] + 1)
Subscript[k, 1][t_, s_] = s^3 /. s -> 1/4*([Tau] + 1)*(r + 1)
Subscript[G, 1][r_] = 1/x[r]
Subscript[k, 2][t_, s_] = -2 (t - s) /. t -> 1/2*([Tau] + 1) /. 
s -> 1/4*([Tau] + 1)*(r + 1)
Subscript[G, 2][r_] = Expand[(x[r])^2]
p[[Tau]_, r_] = Subscript[k, 2][t, s]*Subscript[G, 2][r]
Integrate[p[[Tau], r], {r, -1, 1}]
pp[[Tau]_, r_] = 
Subscript[k, 1][t, s]*Subscript[G, 1][r] // Expand // FullSimplify
(*Integrate[pp[[Tau],r],{r,-1,1}]//runing....*)
(*Simplify[Series[ToRadicals@Normal[Integrate[pp[[Tau],r],{r,-1,1}]],
{[Tau],tableoft[[1]],tableoft[[2]]}]]*)
Int[pp[[Tau], r], r]

by integrate:

3.44583415018366`*^-6 RootSum[
Subscript[a, 0] - 2 Subscript[a, 1] + 2 #1 Subscript[a, 1] + 
3 Subscript[a, 2] - 8 #1 Subscript[a, 2] + 
4 #1^2 Subscript[a, 2] - 4 Subscript[a, 3] + 
20 #1 Subscript[a, 3] - 24 #1^2 Subscript[a, 3] + 
8 #1^3 Subscript[a, 3] + 5 Subscript[a, 4] - 
40 #1 Subscript[a, 4] + 84 #1^2 Subscript[a, 4] - 
64 #1^3 Subscript[a, 4] + 16 #1^4 Subscript[a, 4] - 
6 Subscript[a, 5] + 70 #1 Subscript[a, 5] - 
224 #1^2 Subscript[a, 5] + 288 #1^3 Subscript[a, 5] - 
160 #1^4 Subscript[a, 5] + 32 #1^5 Subscript[a, 5] + 
7 Subscript[a, 6] - 112 #1 Subscript[a, 6] + 
504 #1^2 Subscript[a, 6] - 960 #1^3 Subscript[a, 6] + 
880 #1^4 Subscript[a, 6] - 384 #1^5 Subscript[a, 6] + 
64 #1^6 Subscript[a, 
 6] &, (Log[1 + r - #1] #1^3)/(Subscript[a, 1] - 
  4 Subscript[a, 2] + 4 #1 Subscript[a, 2] + 10 Subscript[a, 3] - 
  24 #1 Subscript[a, 3] + 12 #1^2 Subscript[a, 3] - 
  20 Subscript[a, 4] + 84 #1 Subscript[a, 4] - 
  96 #1^2 Subscript[a, 4] + 32 #1^3 Subscript[a, 4] + 
  35 Subscript[a, 5] - 224 #1 Subscript[a, 5] + 
  432 #1^2 Subscript[a, 5] - 320 #1^3 Subscript[a, 5] + 
  80 #1^4 Subscript[a, 5] - 56 Subscript[a, 6] + 
  504 #1 Subscript[a, 6] - 1440 #1^2 Subscript[a, 6] + 
  1760 #1^3 Subscript[a, 6] - 960 #1^4 Subscript[a, 6] + 
  192 #1^5 Subscript[a, 6]) &]

but since coefficients of this function are as parameters, so i could not get any reasonable answer from mathematica.I got rootsum function, then i used Rubi and Int function but it gave me Removed[Int][…]!
Please help me to finding this integral

by Int[]

1/64 (1 + [Tau])^3 Removed["Int"][1/(
Subscript[a, 0] - Subscript[a, 2] + Subscript[a, 4] + 
8 r^3 (Subscript[a, 3] - 4 Subscript[a, 5]) + 
32 r^5 Subscript[a, 5] + 
2 r (Subscript[a, 1] - 2 Subscript[a, 3] + 3 Subscript[a, 5]) + 
16 r^4 (Subscript[a, 4] - 5 Subscript[a, 6]) - Subscript[a, 6] + 
64 r^6 Subscript[a, 6] + 
4 r^2 (Subscript[a, 2] - 3 Subscript[a, 4] + 6 Subscript[a, 6])), 
r] + 3/64 (1 + [Tau])^3 Removed["Int"][r/(
Subscript[a, 0] - Subscript[a, 2] + Subscript[a, 4] + 
8 r^3 (Subscript[a, 3] - 4 Subscript[a, 5]) + 
32 r^5 Subscript[a, 5] + 
2 r (Subscript[a, 1] - 2 Subscript[a, 3] + 3 Subscript[a, 5]) + 
16 r^4 (Subscript[a, 4] - 5 Subscript[a, 6]) - Subscript[a, 6] + 
64 r^6 Subscript[a, 6] + 
4 r^2 (Subscript[a, 2] - 3 Subscript[a, 4] + 6 Subscript[a, 6])), 
r] + 3/64 (1 + [Tau])^3 Removed["Int"][r^2/(
Subscript[a, 0] - Subscript[a, 2] + Subscript[a, 4] + 
8 r^3 (Subscript[a, 3] - 4 Subscript[a, 5]) + 
32 r^5 Subscript[a, 5] + 
2 r (Subscript[a, 1] - 2 Subscript[a, 3] + 3 Subscript[a, 5]) + 
16 r^4 (Subscript[a, 4] - 5 Subscript[a, 6]) - Subscript[a, 6] + 
64 r^6 Subscript[a, 6] + 
4 r^2 (Subscript[a, 2] - 3 Subscript[a, 4] + 6 Subscript[a, 6])), 
r] + 1/64 (1 + [Tau])^3 Removed["Int"][r^3/(
Subscript[a, 0] - Subscript[a, 2] + Subscript[a, 4] + 
8 r^3 (Subscript[a, 3] - 4 Subscript[a, 5]) + 
32 r^5 Subscript[a, 5] + 
2 r (Subscript[a, 1] - 2 Subscript[a, 3] + 3 Subscript[a, 5]) + 
16 r^4 (Subscript[a, 4] - 5 Subscript[a, 6]) - Subscript[a, 6] + 
64 r^6 Subscript[a, 6] + 
4 r^2 (Subscript[a, 2] - 3 Subscript[a, 4] + 6 Subscript[a, 6])), 
r]